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

Dodds, Seth D.; Panjabi, Manohar M.; Slade, Joseph F.

doi:10.1016/j.jhsa.2005.09.014

Cited by 124 publications

(80 citation statements)

References 33 publications

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“…The bone density is greatest in the scaphoid poles providing the best fixation (43). The longer the screw the morer igid the fixation because forces arer educed along the screw,r educing the forces at the fracture site (44).…”

Section: Discussionmentioning

confidence: 99%

Retrospective Review of 234 Scaphoid Fractures and Nonunions Treated with Arthroscopy for Union and Complications

Slade

Gillon

2008

Scand J Surg

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the purpose of this paper is to retrospectively review 234 consecutive cases of scaphoid fractures and nonunions treated using arthroscopy with the dorsal percutaneous implantation of ah eadless compression screw for healing and complications. solid union of fracture is determined by ct scan. we identified 126 acute injuries, including 65 proximal pole fractures; 67 grossly displaced fractures; 12 trans-scaphoid perilunate dislocations including four trans-scaphoid trans-capitate fractures; and ten combined scaphoid and distal radius fractures. 108 scaphoid nonunions were identified. 98 were correctly aligned and ten had ah umpback deformity which was correctable using arthroscopic assisted reduction techniques at the time of surgery.8 2p resented with af racture gap 2mm or greater requiring percutaneous bone grafting. 12 cases of avascular necrosis (avn) were identified by mRi. 20 nonunions had surgery performed at other institutions. the mean time to surgery for the nonunions was 20 months.99% union rate of acute scaphoid fractures was obtained by 12 weeks, as determined by ct scan. twoc omplications were identified (3%). one case of delayed healing was identified. this delayed union was treated with percutaneous bone grafting and continued on to heal uneventfully.the other complication was acase of volar trans-scaphoid peri-lunate dislocation. while the fracture healed, the patient developed at raumatic dislocation requiring ac apitate-lunate arthrodesis. tr eatment of scaphoid nonunions resulted in ten cases of delayed healing, which were treated with repeat percutaneous bone grafting. this represented a9 %c omplication rate. of the ten cases of delayed unions that were re-bone grafted, four failed to heal by nine months. this resulted in a 96% union rate of our nonunion group by nine months. when acute fracture healing was compared to nonunions the average healing of acute fractures as determined by ct scanning measuring trabecular bridging was 12 weeks, while the average healing of nonunions was 22 weeks. we conclude that the dorsal percutaneous treatment of scaphoid fractures and nonunions using arthroscopy is safe and effective. ct scans to evaluate scaphoid healing by measuring trabecular bridging at the fracture site was determined to be an excellent modality to evaluate scaphoid healing. while not witnessed in this series, the potential for complications requires proper training.

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Section: Discussionmentioning

confidence: 99%

Retrospective Review of 234 Scaphoid Fractures and Nonunions Treated with Arthroscopy for Union and Complications

Slade

Gillon

2008

Scand J Surg

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“…18 The implications of central screw placement have been evaluated in biomechanical studies of osteotomized fresh cadaveric scaphoid waist fracture repairs. [19][20][21] In one study, central placement was shown to confer greater stiffness and load at failure, compared with eccentric placement. 21 Although the same screw type was utilized in all three cases, we do not attribute secondary fracture risk to hardware make or model.…”

Section: Discussionmentioning

confidence: 99%

Scaphoid Proximal Pole Fracture Following Headless Screw Fixation

et al. 2015

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Nondisplaced scaphoid waist fractures may be managed nonoperatively, but require strict and prolonged immobilization. Fracture nonunion is a troublesome complication that leads to prolonged casting or secondary surgery and, if untreated, to carpal collapse and degenerative arthritis. 1,2 Unstable or displaced fractures, fracture-dislocations, and fractures involving the proximal pole require anatomic reduction with rigid fixation. Modern headless compression screws demonstrate high union rates, rapid recovery, and good-to-excellent outcomes in most series. 1,3-8 We were unable to identify reports detailing the potential for secondary proximal pole fracture following scaphoid screw fixation.In this series we describe three young men with scaphoid fracture nonunion that healed after antegrade headless compression screw fixation (Acumed, Hillsboro, OR, USA). Months later, the men presented with secondary fracture of the proximal pole (►Table 1). A consistently proximal and volar fracture pattern was observed that was contiguous with the screw insertion site. The purpose of this case series is to report our experience and raise awareness of a possible risk of retained hardware following antegrade scaphoid nonunion fixation, offer treatment strategies, and report outcomes. Case 1A 15-year-old right-handed lacrosse player presented to our institution after 3.5 months of sport-related left wrist pain had not abated. A scaphoid fracture had been treated as a AbstractBackground 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.

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“…This leads to better purchase of the screw in the densest cancellous bone, which is located at the poles. It has been reported that a screw buried 2 mm under the chondral surface of the proximal and distal poles of the scaphoid offers more biomechanical stability [14]. This cannot always be achieved when using screws with a diameter of 4.0 mm or greater at the proximal pole (pTAD upper 95% CI, 2.01 mm).…”

Section: Discussionmentioning

confidence: 99%

“…For our comparison, maximum screw length was used. Some surgeons do not use the maximum screw length but subtract 4 mm of the measured scaphoid length to avoid prominence of the screw at the articular surface, which could lead to chondral wear [14]. The ability of the screw to be placed 2 mm under the surface at the proximal and distal poles (pTAD and dTAD) is therefore clinically more important.…”

Section: Discussionmentioning

confidence: 99%

“…In the clinical setting, a shorter and centrally placed screw has the advantage of avoiding prominence at the chondral surface. However, a study by Dodds et al [14] showed that compared with a long screw that ends just under the chondral surface, a short and centrally placed screw does not take advantage of the holding power of the cancellous bone throughout the scaphoid length. Therefore, a long centrally placed screw, with purchase of the screw threads in the subchondral bone, provides better fixation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

Meermans¹,

Verstreken²

2012

Clinical Orthopaedics &Amp; Related Research

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Background Screw fixation of scaphoid fractures has gained popularity. A long central screw has been shown to be biomechanically advantageous. Questions/purposes We compared the ability of different screw designs to obtain this goal and determined the influence of sex and approach on screw length. Methods We performed all measurements on threedimensional 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. Results The length of the scaphoid along its central axis was longer in men (mean, 27.14 mm; standard error of the mean, 0.97 mm) than in women (mean, 23.86 mm; standard error of the mean, 0.37 mm). The screw length that can be used was longer in the volar approach (mean, 23.72 mm; standard error of the mean, 0.19 mm) than in the dorsal approach (mean, 23.31 mm; standard error of the mean, 0.19 mm) regardless of the screw design. Screws with a trailing thread diameter greater than 3.9 mm and leading thread diameter greater than 3.0 mm were shorter. Conclusions 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 3.9 mm or less.

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

Cited by 124 publications

References 33 publications

Retrospective Review of 234 Scaphoid Fractures and Nonunions Treated with Arthroscopy for Union and Complications

Retrospective Review of 234 Scaphoid Fractures and Nonunions Treated with Arthroscopy for Union and Complications

Scaphoid Proximal Pole Fracture Following Headless Screw Fixation

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

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