Surgical Implant Generation Network Implant Follow-up: Assessment of Squat and Smile and Fracture Healing

To evaluate the reliability, sensitivity, and specificity of the Squat and Smile (S&S) test, a clinical photographic follow-up, in determination of fracture healing and to assess the extent of continued fracture healing beyond 1-year postoperation.

Retrospective review of the Surgical Implant Generation Network (SIGN) database.

The S&S test is utilized in low-resource settings where the SIGN intramedullary nail is used due to unavailability of intraoperative fluoroscopy.

One hundred fifty patients undergoing fracture fixation utilizing SIGN intramedullary nails with data available at least 1 year (9-16 months) after surgery.

None.

We extracted clinical data and calculated scores for the S&S photographs and radiographs at the 1-year (9-16 month postoperative) follow-up and last follow-up available beyond that. We analyzed the sensitivity of S&S scoring, using Radiographic Union Scale for Tibia fracture scores as the gold standard for fracture union.

Of the 126 patients analyzed, 21% were found to have incomplete healing at 1 year, whereas 17% of the 64 patients with further follow-up past 1 year had incomplete healing. We found that both S&S and radiographic fracture healing scores had good interrater reliability (k = 0.73-0.78 for S&S and 0.94 for radiographs). The S&S test had poor sensitivity (0.11) and specificity (0.85) in determining fracture healing at the 1-year follow-up.

The S&S scoring method was reliable but neither sensitive nor specific for determining fracture healing at 1 year. Fractures deemed incompletely healed by radiographic evaluation at 1 year after SIGN implant may still have the potential to heal over time.

Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.