Scaphoid Malunion: Incidence, Predictors, and Outcomes

Abstract

Background Scaphoid malunion is rarely reported. Previous literature has attributed loss of carpal height and degenerative changes to scaphoid malunion, but the percentage of asymptomatic malunions remains unknown.

Purpose The authors of this study aim to define predictors of malunion and outcomes associated with scaphoid malunion.

Methods Institutional board review was obtained prior to evaluating medical records of patients 18 years and older who were treated for scaphoid fractures and/or nonunion between 2000 and 2020. The following data were collected for each patient: age, gender, fracture location, surgical technique, time to union, and whether malunion resulted. Malunion was defined using a lateral intrascaphoid angle (LISA) >45 degrees and height-to-length ratio (HLR) >60. Pain scores, range of motion (ROM), and secondary surgery were also evaluated.

Results Overall, 355 scaphoid injuries, including 196 acute fractures and 159 nonunions, were evaluated in this analysis. Of these, 55 scaphoids (15%) met the definition of malunion. Of these patients, 23% were female. The mean age at the time of injury was 29 years. Nonunion cases were more likely than acute cases to be associated with malunion. Proximal pole fractures were more likely to associated with malunion than waist fractures. When controlling for nonunion and fracture location, malunited scaphoids were not associated with any significant difference in pain score, ROM, or secondary surgery, compared with nonmalunion cases. A total of 10 patients (3.3%) without malunion and 2 patients (3.6%) with malunion went on to a secondary surgery. Final extension/flexion was 67/67 degrees and 56/59 degrees in nonmalunion and malunion groups, respectively, but these differences were not significant.

Conclusion Compared with scaphoid injuries that do not result in malunion, scaphoid injuries that heal into malunion have similar outcomes. While scaphoid malunion in a single case or series may be associated with poor outcomes, this study suggests that scaphoid malunions do not have worse functional outcomes.

Level of Evidence This is a Level IV study.

Keywords

scaphoid - malunion - function - pain - union - surgery - fracture - SNAC

Note

The work was performed at the Stanford University.

Ethical Approval

Approval was obtained from the Institutional Review Board prior to initiating this study.

Publication History

Received: 20 June 2021

Accepted: 17 May 2022

Article published online:
06 July 2022

• References

• 1 Amadio PC, Berquist TH, Smith DK, Ilstrup DM, Cooney III WP, Linscheid RL. Scaphoid malunion. J Hand Surg Am 1989; 14 (04) 679-687
• 2 Burgess RC. The effect of a simulated scaphoid malunion on wrist motion. J Hand Surg Am 1987; 12 (5, pt. 1): 774-776
• 3 Lynch NM, Linscheid RL. Corrective osteotomy for scaphoid malunion: technique and long-term follow-up evaluation. J Hand Surg Am 1997; 22 (01) 35-43
• 4 Megerle K, Harenberg PS, Germann G, Hellmich S. Scaphoid morphology and clinical outcomes in scaphoid reconstructions. Injury 2012; 43 (03) 306-310
• 5 Lee CH, Lee KH, Lee BG, Kim DY, Choi WS. Clinical outcome of scaphoid malunion as a result of scaphoid fracture nonunion surgical treatment: a 5-year minimum follow-up study. Orthop Traumatol Surg Res 2015; 101 (03) 359-363
• 6 Forward DP, Singh HP, Dawson S, Davis TRC. The clinical outcome of scaphoid fracture malunion at 1 year. J Hand Surg Eur Vol 2009; 34 (01) 40-46
• 7 Afshar A, Mohammadi A, Zohrabi K, Navaeifar N, Sami SH, Taleb H. Correlation of reconstructed scaphoid morphology with clinical outcomes. Arch Bone Jt Surg 2015; 3 (04) 244-249
• 8 Luchetti TJ, Hedroug Y, Fernandez JJ, Cohen MS, Wysocki RW. The morphology of proximal pole scaphoid fractures: implications for optimal screw placement. J Hand Surg Eur Vol 2018; 43 (01) 73-79
• 9 Tang JB. Re: Levels of experience of surgeons in clinical studies. J Hand Surg Eur Vol 2009; 34 (01) 137-138
• 10 Seltser A, Suh N, Chambers SB, MacDermid JC, Grewal R. Scaphoid malunion clinical and radiographic outcomes at a minimum of 4 years follow-up. J Hand Surg Am 2020; 45 (09) 883.e1-883.e7
• 11 Smith DK, Cooney III WP, An KN, Linscheid RL, Chao EY. The effects of simulated unstable scaphoid fractures on carpal motion. J Hand Surg Am 1989; 14 (2, pt. 1): 283-291
• 12 Boe CC, Amadio PC, Kakar S. The management of the healed scaphoid malunion: what to do?. Hand Clin 2019; 35 (03) 373-379
• 13 Gillette BP, Amadio PC, Kakar S. Long-term outcomes of scaphoid malunion. Hand (N Y) 2017; 12 (01) 26-30
• 14 El-Karef EA. Corrective osteotomy for symptomatic scaphoid malunion. Injury 2005; 36 (12) 1440-1448
• 15 Fernández DL, Martin CJ, González del Pino J. Scaphoid malunion. The significance of rotational malalignment. J Hand Surg [Br] 1998; 23 (06) 771-775
• 16 Ring D, Patterson JD, Levitz S, Wang C, Jupiter JB. Both scanning plane and observer affect measurements of scaphoid deformity. J Hand Surg Am 2005; 30 (04) 696-701
• 17 Bain GI, Bennett JD, MacDermid JC, Slethaug GP, Richards RS, Roth JH. Measurement of the scaphoid humpback deformity using longitudinal computed tomography: intra- and interobserver variability using various measurement techniques. J Hand Surg Am 1998; 23 (01) 76-81
• 18 Roh YH, Noh JH, Lee BK. et al. Reliability and validity of carpal alignment measurements in evaluating deformities of scaphoid fractures. Arch Orthop Trauma Surg 2014; 134 (06) 887-893
• 19 Sanders WE. Evaluation of the humpback scaphoid by computed tomography in the longitudinal axial plane of the scaphoid. J Hand Surg Am 1988; 13 (02) 182-187