Aktueller Stand der Kahnbeinchirurgie

Conservative and various operative treatment options are available for fractures of the scaphoid. Nonunion of the scaphoid requires an operative treatment. Of the patients who underwent surgery for fractures of the scaphoid from 1999 to 2001, 74 were treated with Herbert screw fixation. Nonunion of the scaphoid in 52 cases was treated by iliac crest bone grafting and Herbert screw implantation following resection of the affected bony parts. The cannulated, self-tapping headless bone screw system (cannulated Herbert screw) was used, which allows for easier implantation of the screw. Bony consolidation was achieved in a high proportion of these cases; bony fusion was achieved in all cases of scaphoid fracture. Operative treatment was followed by healing in 47 cases of scaphoid nonunions.     

Pediatric scaphoid nonunion

PURPOSE: To report the outcome of pediatric scaphoid nonunions treated with a Herbert screw and bone graft. METHODS: This is a retrospective review of 12 cases of scaphoid nonunion in 12 skeletally immature patients treated with a uniform approach consisting of open reduction, iliac crest bone grafting and Herbert screw fixation. All patients were boys and presented with nonunions of the scaphoid waist. The final follow-up evaluation was at a mean of 32 months, ranging from 22 to 45 months, and consisted of assessing anatomic snuffbox tenderness, wrist arc of motion, grip strength, calculation of the Modified Mayo Wrist score, and assessment of union based on plain radiographs. RESULTS: At the latest follow-up evaluation, all patients were pain free (including absence of snuffbox tenderness) except one who experienced slight discomfort during extreme activities. There was no statistically significant difference in the arc of motion between the surgically treated and healthy sides, and the average grip strength was 96% that of the contralateral extremity. Clinical and radiographic union was present in all cases at a mean of 3.4 months after surgery. The Modified Mayo Wrist score was excellent in 11 patients and good in 1. There were no complications. CONCLUSIONS: Open reduction and internal fixation with a Herbert screw reliably obtained union in all patients. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.     

Treatment of scaphoid nonunion by radical curettage, trapezoidal iliac crest bone graft, and internal fixation with a Herbert screw

Ten adult male patients with scaphoid nonunions were treated by radical curettage, trapezoidal iliac crest bone grafting, and internal fixation with a Herbert screw. The mean patient age was 24.7 years, and the mean duration of the nonunion before surgery was 37.3 months. Mean follow-up time was 30.4 months. Nine of the ten nonunions healed, although one patient required a second bone-grafting procedure. The mean postoperative grip strength was 45.0 kg, and the mean postoperative pinch strength was 11.5 kg. The mean postoperative range of motion was volar flexion, 76.1 degrees; dorsiflexion, 74.2 degrees; radial deviation, 22.1 degrees; and ulnar deviation, 40.1 degrees. The scapholunate angle decreased from a mean of 72.8 degrees preoperatively to 60.6 degrees postoperatively (p less than 0.025). The mean carpal index was 0.57 postoperatively. Mean scaphoid length increased postoperatively and was within 0.2 mm of the opposite (normal) scaphoid in every patient except the single patient with a persistent nonunion (p less than 0.025). All patients returned to work (eight as laborers), and nine of ten wrists were subjectively rated as good or excellent. The results of the series suggests that treatment of displaced scaphoid nonunion by radical curettage, trapezoidal iliac crest bone grafting, and internal fixation with a Herbert screw is an effective method of treatment that reconstitutes scaphoid anatomy and promotes excellent wrist function.     

背侧入路经皮加压螺钉内固定治疗舟骨骨折的临床研究

目的介绍背侧入路经皮加压螺钉内固定治疗舟骨骨折的适应证、手术方法和疗效。方法2009年4~10月,采用背侧入路经皮加压螺钉固定小切口空心钉技术治疗6例急性舟骨骨折的患者,骨折分型为HerbertB2,B3型。术中以Lister结节为标志,于其远端0·5~1cm处触及舟骨近极,在导针引导、C型臂监视下、沿舟骨轴线打入合适长度的加压螺钉。结果6例患者均有初步随访资料,随访时间为4至6个月,平均5个月。B2型骨折平均愈合时间为8周,B3型骨折平均愈合时间为12周;恢复工作时间平均为14d;活动度达到健侧90%以上;无疼痛等不适感觉。没有并发症。结论背侧入路经皮加压螺钉技术治疗急性舟骨骨折创伤小,根据骨折类型不需外固定或外固定时间较保守治疗缩短,愈合率高,治疗结果满意。     

闭合复位经皮Herbert螺钉内固定治疗新鲜稳定型舟骨腰部骨折

目的：观察闭合复位经皮Herbert螺钉内固定治疗新鲜稳定型舟骨腰部骨折的临床疗效。方法对采用闭合复位经皮Herbert螺钉内固定治疗的12例新鲜稳定型舟骨腰部骨折患者进行随访,采用修订后Mayo腕关节评分标准对临床效果进行评价。结果所有患者均获得随访,随访时间13~23个月（平均15个月）,无感染、螺钉松动、过敏排斥反应及关节炎的发生。所有患者骨折均愈合,骨折愈合时间为8~14周,平均10周。按修订后Mayo腕关节评分标准：优7例,良4例,可1例,优良率91.7%。结论闭合复位经皮Herbert螺钉内固定治疗新鲜稳定型舟骨腰部骨折,具有操作简单,固定可靠,并发症少及能早期进行功能锻炼等优点。     

Retrograde compression screw fixation of acute proximal pole scaphoid fractures

Seventeen consecutive patients with acute unstable proximal pole scaphoid fractures were managed over the past 5 years with open reduction and internal fixation. Four fractures were displaced, with greater than 1 mm of fragment offset and intercarpal malalignment. The operative technique consisted of a dorsal approach to the scaphoid, radius bone grafting, and freehand retrograde Herbert compression screw fixation. The patients were evaluated at an average of 37 months (range, 12-63 months) after surgery. All fractures healed within 13 weeks (average, 10 weeks). Functional wrist range of motion and grip strength were achieved in all patients. No patients developed osteonecrosis or radioscaphoid arthritis. Open reduction and internal fixation rather than primary casting is a better means of reducing the complications of delayed union, nonunion, and irreparable osteonecrosis that often occur after acute proximal pole scaphoid fracture treated with cast immobilization.     

Kahnbeinfrakturen mit palmarer Trümmerzone

Two cases of acute scaphoid fractures of the middle third with palmar comminution were treated with cancellous bone transplantation and Herbert screw fixation. Despite 6 weeks of cast immobilization, secondary loss of reduction resulted in primary grade dislocation in one patient. In the other patient scaphoid dislocation led to dorsiflexed intercalated segment instability and the need for screw removal due to secondary joint irritation. As a consequence the authors recommend the use of cortical bone grafting of the iliac crest in cases where palmar defects occur after reduction of the scaphoid.     

A biomechanical comparison of scaphoid fixation with bone grafting using iliac bone or distal radius bone

PURPOSE: Although many scaphoid fractures may be treated by immobilization, complex scaphoid fractures generally require bone grafting with internal fixation. A preferred source of bone graft for scaphoid grafting is the iliac crest. Donor site morbidity from iliac crest harvest, however, is a known complication, and the comparable strength and osteogenic properties of bone harvested from other sites are unclear. To this end, we have conducted a cadaveric comparative investigation of the strength of scaphoid nonunions with bone graft and internal fixation using either iliac crest bone or distal radius bone. METHODS: Ten paired, human, fresh-frozen cadaveric wrists were used to create a standard midwaist wedge osteotomy into which identically shaped distal radius or iliac crest bone wedges were internally fixed using headless compression screws. After bone density and computed tomography assessment of the bones, benchtop biomechanical testing was conducted to compare the strength of the scaphoids after iliac and distal radius grafting, at 2-mm displacement, and at failure. RESULTS: Analysis of scaphoid length, width, height, weight, density, and screw placement revealed no statistical differences between both bone graft groups. Although not significant, scaphoid nonunions grafted with distal radius bone evidenced a reduced load (3.23 +/- 0.26 Nm) to 2-mm displacement compared with iliac crest bone (5.97 +/- 0.68 Nm). Similarly, though not significant, scaphoids grafted with distal radius bone showed a reduced load (4.18 +/- 0.30 Nm) to failure compared with iliac crest bone grafting (6.42 +/- 0.66 Nm). Although no significance was found between the 2 grafting methods, a trend toward greater strength in the iliac crest graft group was observed. CONCLUSIONS: Given the comparable biomechanical strength shown between iliac and distal radius bone in this study and the simplified surgical technique of distal radius harvesting, the data justify use of distal radius bone as a viable alternative donor source in scaphoid fracture treatment.     

Technical factors related to Herbert screw fixation

We reviewed 24 patients treated for an acute fracture or a nonunion of the scaphoid bone using the Herbert screw. Mean follow-up in 22 patients who returned for examination was 17 months. The overall union rate was 67% for both acute fractures and nonunions. Fracture healing correlated strongly with technical factors of the procedure. The fracture failed to heal in seven of nine cases with poor scaphoid realignment, inaccurate jig placement, or improper screw length for a nonunion rate of 78%. Conversely, without these technical problems, 14 (93%) of 16 fractures achieved union. Applying Herbert's criteria, a satisfactory rating for clinical function was achieved in 59% of all patients and for patient satisfaction in 68% of all patients. Although the postoperative immobilization period was reduced using the screw, the final functional result in our nonunions was similar to that reported for the Russe bone grafting procedure. Appropriate modifications of the standard technique and recognition of equipment limitations may improve union rates.     

Management of proximal scaphoid bone pseudarthroses and fractures with the mini-Herbert screw via a dorsal approach

32 patients, aged 16 to 49 years, were treated by osteosynthesis using the Herbert mini screw. The indications were five fractures (type B3, Herbert classification), two delayed unions (type C) and 25 nonunions (type D1 to D3, Filan and Herbert classification). Six patients received no bone grafts, 19 received cancellous bone graft from the radius. An interpositional iliac crest bone graft was used in four, and a vascularized bone graft from the distal radius in three cases respectively. The average postoperative immobilisation in a forearm splint was nine weeks. 26 patients could be recruited for clinical follow-up at an average of 14,5 months. The radiological results were assessed in 30 cases (94%). Bony consolidation was achieved in 26 cases (100% of the fractures, 84% of the nonunions). In three cases a loosening of the screw, and in three further cases a dislocation into the radiocarpal joint were observed. A humpback deformity was present in four cases. Three patients showed a persisting nonunion, one patient a fibrous union. Early degenerative changes of the radiocarpal joint were observed in six cases. The clinical follow up examination showed an average grip strength of 91% (JAMAR II), 94% for the three finger, and 95% for the pinch grip compared to the contralateral side. The mean postoperative pain score on the visual analog scale was one for resting conditions, eleven for motion and 33 under stress. The range of motion was 79% of the opposite side for extension/flexion and 83% for radial/ulnar deviation. The average DASH-score reached 15 points. The Herbert mini screw has proven to be a reliable implant for reconstruction of proximal pole fractures and nonunions of the scaphoid.     

Open reduction and internal fixation of acute displaced scaphoid waist fractures

Fourteen consecutive patients with acute displaced scaphoid waist fractures were treated with open reduction and internal fixation. The operative technique consisted of anatomic reduction of the displaced scaphoid waist fracture, correction of carpal instability, radial bone grafting for comminution, and internal fixation with K-wires or Herbert screw. The patients were evaluated an average of 26 months (range, 4-48 months) after surgery. Thirteen of the 14 (93%) fractures united. The average time to union was 11.5 weeks (range, 8-20 weeks). Fracture union was confirmed with trispiral tomography. Final radiographic assessment consistently revealed a healed scaphoid fracture, restored intrascaphoid alignment, and no evidence of carpal instability. All patients regained functional wrist range of motion (wrist extension, 57 degrees; wrist flexion, 52 degrees ) and grip strength. Open reduction and internal fixation of acute displaced scaphoid waist fractures restores scaphoid alignment and leads to predictable union. Early operative intervention avoids malunion and carpal instability that often occurs with closed management of these complex fractures.     

陈旧性舟骨骨折的手术疗效分析

目的 探讨陈旧性舟骨骨折的治疗方法及临床疗效.方法 2005年6月至2008年6月,对16例陈旧性舟骨腰部骨折患者,采用腕关节背侧入路,去除骨折处硬化骨后加自体骨植骨,并用Herbert螺钉加克氏针进行固定.术后定期复查X线片,观察骨折愈合情况.根据Krimmer评分评估腕关节功能.结果 术后16例获得随访(平均为8.5个月),所有骨折均获得愈合,平均愈合时间为16周.按Krimmer评分:优8例,良5例,可2例,差1例;优良率达81.3%.结论 对于陈旧性舟骨骨折,通过自体骨植骨及Herbert钉加克氏针内固定,能取得较理想的临床效果.

Abstract：

Objective To discuss the surgical methods and treatment effects of old scaphoid fractures.Methods From June 2005 to June 2008, 16 cases of old scaphoid waist fractures were treated by debridement of necrotic bone, autologous bone graft and Herbert screw plus Kirschner wire internal fixation through a dorsal approach. Postoperative X-rays were taken on a regular basis to observe fracture healing. Wrist function was evaluated according to Krimmer score. Results Postoperatively the 16 cases were follow-up for an average of 8.5 months. All the fractures healed and the average healing time was 16 weeks. Krimmer score determined wrist function to be excellent in 8 cases, good in 5 cases, fair in 2 cases and poor in 1 case. The overall satisfactory rate was 81.3%. Conclusion Herbert screw and K-wire internal fixation combined with autologous bone graft can attain good clinical results in the treatment of old scaphoid fiactures at the waist.     

Comparison of headless screws used in the treatment of proximal nonunion of scaphoid bone

Screws with different levels of compression force are available for scaphoid fixation and it is known that the Acutrak screw generates greater compression than the Herbert screw. We retrospectively compared two types of headless compression screw for their effectiveness in the repair of scaphoid nonunion. Twenty-nine cases of proximal scaphoid nonunion were surgically treated with non-vascularised bone graft: the Acutrak screw was used in 17 patients and the cannulated Herbert screw in 12 patients. Wrist range of motion, Mayo wrist score, grip strength and QuickDASH scores were indicators used for the functional evaluation. Radiographic findings were assessed for consolidation of nonunion and signs of arthrosis. The mean follow-up time was 49.2 months (range 12–96). Statistically, there was no significant difference between the Acutrak and Herbert screw types in terms of functional evaluation and time required for consolidation. Greater compression did not influence the functional outcome, consolidation rate or time to consolidation. The need for greater compression in the treatment of proximal scaphoid nonunions is thus questionable because it may increase the risk of proximal fragment communition.     

Changing concepts in the treatment of scaphoid nonunion: vascularized bone graft based on the 1,2 intercompartmental supraretinacular artery

Scaphoid fractures are a common injury encountered by hand surgeons. Fracture union can generally be achieved with cast immobilization or open reduction and internal fixation. Occasionally, these fractures fail to heal despite proper treatment or a nonunion may result from an unrecognized fracture. Traditionally, scaphoid nonunions have been treated with autologous bone grafts from the iliac crest; however, if the proximal pole is poorly vascularized, union may be difficult to achieved. Vascularized bone grafts are an alternate technique for difficult scaphoid nonunions, particularly those with avascular necrosis of the proximal segment. A graft from the distal radius based on the 1,2-intercompartmental supraretinacular artery is an excellent option for scaphoid nonunions. This article describes the anatomy of the 1,2-ICSRA and the surgical technique of harvesting a graft based on this pedicle. Vascularized bone grafts represent a changing concept in the treatment of scaphoid nonunions and provide a powerful tool for a difficult problem. The indications for this procedure continue to increase.     

Retrograde Herbert screw fixation for treatment of proximal pole scaphoid nonunions

Most nonunions of the carpal scaphoid bone can be treated with a high rate of success by use of conventional bone grafting techniques. However, fractures with a small proximal pole fragment may be difficult to treat by use of these techniques. Nine patients with nonunion and three patients with unstable proximal pole fractures were treated with retrograde dorsal Herbert screw fixation and adjunctive bone grafting. Follow-up averaged 25 months. Of the 12 patients, the fracture healed in 11 and one fracture remained ununited. This technique has been successful in our practice and should be considered in the treatment of small proximal pole nonunions and displaced proximal pole fractures.     

Current Concepts in the Treatment of Scaphoid Fractures

Abstract Fractures of the carpus are frequent injuries and typically result from of a fall onto the outstretched hand. Scaphoid fractures are the second most frequent fracture type of the hand (80%). 95% of the patients with acute scaphoid fractures are male, and the average age is approximately 25 years. Conservative treatment of acute scaphoid fractures with immobilization in a plaster cast was the therapy of choice for a long time. Surgical treatment was reserved to severe dislocated fractures only. A progress could be obtained by the principle of intramedullary fixation, whose forerunner is represented by the Herbert screw, and the introduction of cannulated screws guaranteed a continuous improvement. The decision to treat the fracture by surgery requires a clear definition of the fracture type. Therefore, precise radiologic technique is mandatory to detect the fracture and to analyze the pathomorphological circumstances. In order to get an exact classification for the decision on how to proceed, three standard X-ray projections (posteroanterior [PA], lateral and Stecher projection) and a CT scan have to be performed. The most well-known classification has been defined by Herbert & Fisher which combines fracture anatomy, stability and disease history in order to derive prognostic and therapeutic criteria. Also, delayed healings and nonunions are considered. To decide on the adequate treatment, a prerequisite for conservative therapy of acute scaphoid fractures is the anatomic position of the scaphoid. Conservative therapy should be reserved to fracture types, which are stable and heal reliably in the lower-arm plaster cast within 6 weeks. All displaced and unstable acute scaphoid fractures should be operated, and whenever possible, rigid internal fixation should be achieved because of interfragmentary compression. Therefore, several intramedullary implants are available for surgical treatment of acute scaphoid fractures, e. g., Herbert screw, Mini Herbert screw, AO screw (cannulated), Acutrac screw (cannulated), or Twin-fix screw (cannulated). With improved surgical and radiologic techniques, most scaphoid fractures are amenable to minimally invasive fixation. The dorsal approach guarantees a good overview in treating proximal pole fractures. Yet, not all types of fractures can be treated in this way. Severely displaced fractures require the classic open palmar approach. In order to prevent the development of a scaphoid nonunion or an advanced carpal collapse (SNAC-wrist), an early and sufficient diagnostic algorithm is necessary. We recommend internal fixation with a cannulated Herbert screw in B1 and B2 fractures and a Mini Herbert screw in fractures of the proximal third (B3). A2 fractures can be treated conservatively. Early diagnosis and operative treatment will shorten the time off work, minimize the risk of nonunion, and reduce the costs of health care in the long term.     

Successful treatment of scaphoid fractures and nonunions using bioabsorbable screws: report of six cases

PURPOSE: A variety of implants have been used for the fixation of scaphoid fractures, but we have found no reports on bioabsorbable screws used for this purpose. We report 6 cases of scaphoid fractures treated with bioabsorbable screws. METHODS: Six patients with scaphoid waist region fractures (3) and nonunions (3) treated using bioabsorbable self-reinforced poly-L-lactide screws. Interposition of a bone graft from the iliac crest was used in 4 cases. Immobilization in a short arm-thumb spica cast was applied after surgery for an average of 8 weeks. RESULTS: Solid union was achieved in 5 cases. Using the Mayo modified Green-O'Brien wrist score, we graded the results as excellent in 1 case, good in 4 cases, and poor in the single case of nonunion. CONCLUSIONS: These results suggest that bioabsorbable self-reinforced poly-L-lactide screws might offer an alternative in the fixation of scaphoid fractures and nonunions in the future, provided that cannulated screws of appropriate size will be available.     

Percutaneous screw fixation or cast immobilization for nondisplaced scaphoid fractures

BACKGROUND: Nondisplaced scaphoid fractures treated with prolonged cast immobilization 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 cannulated screw has resulted in a shorter time to union and to return to work or sports. The purpose of this prospective, randomized study was to compare cast immobilization with percutaneous cannulated screw fixation of nondisplaced scaphoid fractures with respect to time to radiographic union and to return to work. METHODS: Twenty-five full-time military personnel with an acute nondisplaced fracture of the scaphoid waist consented to be randomized to either cast immobilization or fixation with a percutaneous cannulated Acutrak screw (Acumed, Beaverton, Oregon) for the purpose of this study. 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: Eleven patients were randomized to percutaneous cannulated screw fixation, and fourteen were randomized to cast immobilization. The average time to fracture union in the screw fixation group was seven weeks compared with twelve weeks in the cast immobilization group (p = 0.0003). The average time until the patients returned to work was eight weeks compared with fifteen weeks in the cast immobilization group (p = 0.0001). There was no significant difference in the range of motion of the wrist or in grip strength at the two-year follow-up evaluation. Overall patient satisfaction was high in both groups. CONCLUSIONS: Percutaneous cannulated screw fixation of nondisplaced scaphoid fractures resulted in faster radiographic union and return to military duty compared with cast immobilization. The specific indications for and the risks and benefits of percutaneous screw fixation of such fractures must be determined in larger randomized, prospective studies.     

1，2伸肌室间支持带上动脉为蒂骨瓣移植治疗舟骨骨折不愈合

目的探讨1,2伸肌室间支持带上动脉（1,2 intracompartmental supraretinacular artery 1,2 ICSRA）的解剖特点及治疗舟骨骨折不愈合的临床疗效。方法2008年7月-2010年9月共收治确诊的舟骨骨折不愈合患者11例,均采用逆行的1,2ICSRA为蒂骨瓣植入术结合Herbert螺钉内固定进行治疗,观察患者的骨折愈合情况及并发症,并以DASH评分对腕关节功能进行评价。结果所有患者均获6～33个月随访,平均17个月。11例患者均获骨性愈合,骨折愈合时间为9～14周。平均12周。术后6个月DASH评分平均为6．5分,腕关节功能接近正常。结论慎重的选择适应证,熟悉相关解剖知识,仔细的手术操作,采用逆行的1,2ICSRA为蒂骨瓣植入术结合Herbeft螺钉内固定治疗舟骨骨折不愈合可取得满意的临床疗效。     

The treatment of scaphoid nonunion. A review of a novel technique using precision bone grafting compared with Herbert screw fixation and bone graft

We have retrospectively reviewed the results of 40 consecutive patients with nonunion of the scaphoid treated by the senior author (PG) between 1993 and 1996. These comprised two groups of patients. Group 1 comprised 20 patients treated between 1993 and 1994, with a Herbert screw and autograft, and Group 2, which also comprised 20 patients treated with the precision bone grafting technique which we describe. The precision bone grafting technique employs simple instrumentation to harvest bone percutaneously from the iliac crest and then insert it at the scaphoid nonunion site. The evaluation consisted of a clinical and radiological assessment of union and wrist function. Our review demonstrates a higher rate of union with the precision bone grafting technique than by the Herbert screw fixation with bone grafting.