Scaphoid non-union is associated with significant morbidity, and up to a 56% risk of post-traumatic arthritis if untreated. Thus, surgical intervention of a scaphoid non-united fracture (SNUF) is important to improve healing and subsequent function. Optimal treatment is still debated and is dependent on various factors including fracture morphology, patient factors, and time since injury. In the context of minimally displaced waist fractures, scaphoid non-union in-situ fixation (SNIF) is a viable treatment modality, and some studies have shown union rates of 89–100%. However, current literature consists of small sample sizes of healthy patients with restrictive inclusion criteria (minimally displaced fractures, no humpback deformity or cystic change at the fracture site, patients treated within 6 months of injury), limiting its relevance to the real-world population. The purpose of our study was to report on the outcomes of SNIF in an inclusive patient population. This is a multi-centre retrospective cohort study investigating in-situ screw fixation of SNUFs treated at tertiary referral hospital. Patients were followed until at least union was achieved or non-union was confirmed. Data on patient demographics, comorbidities, operative details and preoperative radiographic data were collected. Our primary outcomes were rate of union and time to union. Secondary outcomes included wrist range of motion, patient reported outcome measures (PROMs) including Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH), Patient Related Wrist Evaluation (PRWE), and Single Assessment Numerical Evaluation (SANE) scores, as well as the rates of complications and revisions. 20 patients age 34±16yrs, 92% male, met the inclusion criteria with mean follow-up of 12.6±8.3 months. Five patients (25%) were smokers, one (5%) was diabetic. Average time from injury to surgery was 11.9±7.4mo. Dorsal approach was used in 75% of cases. All patients had fixation with a single 3.5mm headless compression screw. Two patients had concomitant bone grafting in-situ through the screw hole. Seven were proximal pole fractures and 13 (63%) were waist fractures. Humpback deformity as measured by height-length ratio (HLR) on sagittal 3D computed tomography imaging was 0.82±0.12 preoperatively and 0.72±0.16 postoperatively. As per Slade and Dodds classification, 17% had grade 3 and 83% had grade 4 cystic changes at the nonunion site. Twelve patients (67%) achieved >50% union at 6 weeks, 14 (82%) by 12 weeks, and 16 (89%) by one year. Four patients (11%) went on to non-union. There were no other post-operative complications, and no patients required revision surgery. Wrist extension (pre-op 50±11 o, post-op 63±13o) and flexion (pre-op 66±18o, post-op 72±15o) improved post-operatively, but as expected, there was no significant change in supination (pre-op 73±12o, post-op 80±10o) or pronation (pre-op 75±11o, post-op 76±7o). Mean post-op PROMs were QuickDASH of 9±7, PRWE 16±11, and SANE 78±19. SNIF is an effective treatment for SNUF with a high rate of union and low complication rate in appropriately selected patients with minimally displaced scaphoid waist non-unions.
Greaves et al. (Wed,) studied this question.