Review Question - QID 219567

Scaphoid Fracture Nonunion Treatment Operative QID: 219567 (OBQ23.140)

QID 219567 (Type "219567" in App Search)

A 28-year-old male presents to the clinic for evaluation of chronic left wrist pain. The patient reports that eight months ago he fell while playing basketball and immediately experienced wrist pain. He subsequently presented to urgent care, where orthogonal views of the wrist were obtained, but no fracture was demonstrated. He was given a wrist splint which he intermittently used for four weeks. Despite this, he continued to experience a dull ache since the event, which has been slowly worsening. On examination, snuffbox tenderness is noted. Radiographs are obtained as shown in Figures A-C. He is subsequently sent for an MRI, as shown in Figure D. Which of the following is true concerning managing this patient's injury?

Type & Select Correct Answer

Type in at least one full word to see suggestions list

The dorsal approach is most appropriate to correct the humpback deformity

15%

129/880

The volar approach should be avoided to mitigate risk of devascularization

11%

99/880

Continued immobilization would likely result in fracture union

29/880

Vascularized autograft has similar union rates in comparison to non-vascularized autograft

55%

480/880

Iliac crest autograft has shown superior union rates in comparison to distal radius autograft

15%

133/880

Select Answer to see Preferred Response

This 28-year-old male presents to the clinic with evidence of a minimally displaced scaphoid waist fracture that went onto nonunion. Vascularized versus non-vascularized autograft has not demonstrated any difference in outcomes in treating scaphoid waist non-unions.

Scaphoid fractures are notorious for their risk for avascular necrosis (AVN), with the purported rate ranging from 15-50%. The risk for AVN increases as the fracture migrates more proximally, with proximal 1/5th scaphoid fractures reportedly having a 100% AVN rate. The gold standard in fracture non-unions with proximal pole AVN is an autograft. However, much debate occurs over the ideal treatment, particularly concerning vascularized versus non-vascularized bone graft, as well as the source of bone graft (iliac crest, medial femoral condyle, distal radius). Ultimately, meta-analyses/systematic reviews have demonstrated no significant difference in union rates between the type and source of autograft.

Duncumb et al. performed a systematic review and meta-analysis of 78 studies totaling 7,671 patients comparing the type (vascularized vs. non-vascularized) and source (distal radius vs. iliac crest) of autograft, noting comparable union rates between vascularized and non-vascularized (82.4 vs. 89.4%, p=0.780), as well as distal radius and iliac crest sources (86.9 vs. 87.6%, p=0.841). The authors conclude vascularized bone grafting does not yield significantly superior results.

Rancy et al. performed a prospective study of 35 patients with proximal pole scaphoid non-unions treated with non-vascularized bone graft. The authors found a 33 of 35 exhibited bony healing by 12 weeks. The authors concluded vascularized bone grafting is often unnecessary in the setting of proximal pole scaphoid non-unions.

Uesato et al. performed a review and the diagnosis and management of scaphoid non-unions, highlighting the several factors precluding the diagnosis of a scaphoid fracture. The authors utilize the Filan and Herbert classification to guide treatment type and necessity of non-union, which the authors preferred to be non-vascularized.

Figures A, B, and C represent AP, oblique, and lateral films demonstrating a minimally displaced oblique scaphoid waist fracture. Figure D demonstrates a decreased T1 signal within the proximal pole of the scaphoid.

Incorrect Answers:
Answer 1: the volar approach has been found to better correct humpback deformities
Answer 2: the dorsal approach risks devascularization to a greater degree than the volar approach
Answer 3: immobilization in this patient would likely not result in union, given the chronicity of the fracture and the presence of AVN in the proximal pole of the scaphoid
Answer 5: one single bone autograft source has not demonstrated superiority over the others