This patient was diagnosed with a scaphoid nonunion. As with many nonunions, it most likely occurred as a result of a missed scaphoid fracture, which we suspect occurred as a result of his injury 7 months ago. The chronicity of his injury (> 6 months) allowed us to classify it as a nonunion rather than a delayed union [4].

Radiographic findings (X-ray and CT) that supported this diagnosis included evidence of a fracture at the waist of the scaphoid without evidence of callus formation or bone bridging the fracture gap, mild sclerosis, and cystic formation [5]. Avascular necrosis (AVN) was ruled out based on the MRI.

The treatment goals for scaphoid nonunions are to achieve bony healing, correct any underlying carpal deformities, and prevent future arthritis. While it may be reasonable to offer a trial of immobilization in cases of delayed union, once patients are greater than 6 months from the initial injury, operative intervention provides a more predictable outcome. Surgical options for scaphoid nonunions include internal fixation (using an open, percutaneous, or arthroscopic approach) with or without bone grafting. The decision to perform internal fixation without the use of bone graft cannot be definitively made until the nonunion has been adequately evaluated. Evaluation includes careful assessment of the preoperative imaging and direct assessment of the scaphoid intraoperatively. Preoperatively, radiographic features that may suggest that a bone graft is not necessary include minimal sclerosis at the nonunion site (less than 1 mm), minimal cyst formation, no collapse or change in the architecture of the scaphoid, and normal vascularity of the proximal fragment [6]. If these criteria are not met, bone grafting will likely be required. The intraoperative evaluation of the scaphoid nonunion is a critical step, which helps to confirm whether bone grafting is required, as preoperative imaging may not always correlate with intraoperative findings [7]. Intraoperative evaluation of the nonunion can be performed open or arthroscopically [7, 8]. Intraoperative features that are compatible with fixation without bone grafting include an intact cartilaginous cap, evidence of only a faint ­nonunion fracture line in the waist of the scaphoid, no humpback deformity , minimal differential movement between proximal and distal fragments, and minimal sclerosis or resorption at the edges of each fracture fragment [8]. For example, Fig. 7.4a and b demonstrates an intact cartilaginous cap upon intraoperative inspection with radiographic evidence of a fracture in the waist of the scaphoid. Internal fixation without bone graft is generally reserved for non-to-minimally displaced fractures, within approximately 6 months of injury, that fit the abovementioned criteria [7–9]. Fixation should be rigid and in our experience this is best achieved with a headless compression screw, following the same technique as with an acute scaphoid fracture. Other methods of fixation (i.e., K-wire fixation) are not recommended as compression at the nonunion site is a key component of the fixation. Postoperatively, a variety of immobilization protocols may be used [6, 8]. If adequate rigid fixation is achieved, early active range of motion may be considered (2 weeks postoperatively) [8]. Alternatively, immobilization from 6 to 12 weeks may be used with an above or below elbow cast (thumb spica or Colles’ cast) [6]. It is our preference to immobilize for 6 weeks in a short-arm thumb spica cast and then begin gradual range of motion exercises once union has been achieved.

In this case, both clinical and radiographic factors contributed to our management decision. We did not entertain a course of further immobilization for two main reasons. First, the patient is an elite hockey player and wished to return to training as soon as possible. Second, a 6-week trial of cast immobilization had already been attempted with no further evidence of progression of union. Radiographic factors (based on preoperative imaging) and our intraoperative assessment contributed to our decision to perform internal fixation with a headless compression screw without bone graft. Based on preoperative imaging (Figs. 7.1 and 7.2), there was minimal displacement, no humpback deformity, minimal sclerosis (less than 1 mm), and no avascular necrosis. Given these factors, our level of suspicion for requiring bone graft was low. However, there was mild cystic formation on the imaging, and the duration since injury was 7 months; therefore, we felt inclined to visually inspect the nonunion intraoperatively. Intraoperative evaluation can be performed arthroscopically or via a volar open approach to the scaphoid. We generally use our preoperative level of suspicion for requiring bone graft to determine whether we assess the scaphoid arthroscopically or through an open volar approach. Arthroscopic evaluation provides the benefit of reduced morbidity if an open approach is not required for a bone graft; however, an open approach allows the surgeon to apply stress across the nonunion that may be more difficult to do arthroscopically. As described above, the duration since injury in this patient is beyond the 6-month window some authors describe for suitability of not requiring a bone graft [9]. Also, there was mild cystic formation at the nonunion site, so we therefore elected to do an open volar approach to the scaphoid because we felt that bone grafting may be necessary and prepared the patient for this possibility.