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

Abstract

Objectives: The aims of this study were 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 one-year post-operation. Design: Retrospective review of the SIGN database. Setting: The S&S test is utilized in low-resource settings where the SIGN intramedullary nail is used due to unavailability of intraoperative fluoroscopy. Patients/Participants: 150 patients undergoing fracture fixation utilizing SIGN intramedullary nails with data available at least one year (9-16 months) post-surgery. Intervention: None Main Outcome Measurements: We extracted clinical data and calculated scores for the S&S photographs and radiographs at the one-year (9-16 months post-operative) follow-up and last follow-up available beyond that. We analyzed the sensitivity of S&S scoring, using radiograph assessment as the gold standard for fracture union. Results: Of the 126 patients analyzed, 21% were found to have incomplete healing at one year, whereas 17% of the 64 patients with further follow-up past one year had incomplete healing. We found that both S&S and radiographic fracture healing scores had good inter-rater 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 one-year follow-up. Conclusions: The S&S scoring method was reliable but neither sensitive nor specific for determining fracture healing at one year. Fractures deemed incompletely healed by radiographic evaluation at one year following SIGN implant may still have the potential to heal over time.

Squat and smile assessment in predicting healing of lower limb fractures fixed with a SIGN nail

“…Moreover, smile/facial expression is more of a subjective perception of the patient (variable pain threshold) as well as that of the observer (variable interpretation) and even few patients can squat comfortably despite nonunion. (particularly hypertrophic transverse nonunion) Surprisingly, the only available study 6 to correlate the Squat and Smile test with fracture healing through SIGN nailing follow-up Table 6 Inter-observer and intra-observer reliability for RUST scoring: Weighted kappa (95% confidence interval; percent agreement). 6 They found a poor sensitivity (11%) and specificity (85%) of S & S test in predicting non-healing of fracture at the one-year follow-up, 6 whereas in our study, we found overall good sensitivity (up to 82.22%) and specificity (up to 63.64%) in predicting fracture healing at minimum one-and-a-half-year follow-up.…”

“…for squatting into a 0 to 2 scale. 6 (Fig: 2) This domain was developed from the literature supporting the importance of the normal squat in activities of daily living. Because the most of the smile ratings were unsure or inconsistent between observers, we decided not to utilize it in assigning a score (Table : 2).…”

“…Because the most of the smile ratings were unsure or inconsistent between observers, we decided not to utilize it in assigning a score (Table : 2). 6 Functional scores from the S & S photograph were assessed and dichotomized, with a score of 2 classified as normal squatting and <2 classified as abnormal squatting.…”

“…Minimizing the likelihood of measurement bias by using a standard tool for radiographic scoring (RUST) 7 and by standardization of Squat and Smile grading among the two observers as described in literature 6 ; calculation of inter and intra-observer reliability by two independent and blinded observers with almost equal clinical experience each for evaluating the x-rays and squatting quality, with reevaluation after a month are the strengths of our study. Moreover, unlike prior study, we evaluated at minimum follow-up of eighteen months (against twelve months), and predicted the probability of healing of fracture.…”

“…5 Surprisingly, we are aware of only one study on prediction of fracture healing with the quality of squatting. (with shorter follow up that our study) 6 Thus we aim to determine whether the S & S test is a suitable proxy tool to assess the fracture healing of lower limb long bone after intramedullary interlocking nailing. We calculated the interobserver and intra-observer reliability (k) of Radiographic Union Score for Tibia (RUST) and S & S grading (on clinical photograph).…”