Functional assessment of long bone fracture healing in Samburu County Referral Hospital (Kenya): the squat and smile challenge

BACKGROUND: The burden of musculoskeletal trauma is increasing in low- and middle-income countries. Due to the low clinical follow-up rates in these regions, the Squat-and-Smile test (S&S) has previously been proposed as a proxy to assess bone healing (BH) capacity after surgery involving bone fractures. This study deals with various aspects of using S&S and bone radiography examination to obtain information about an individual's ability to recover after a trauma. In summary, we performed the S&S test to assess the possibility of recovering biomechanical function in lower limbs in a remote area of Kenya (Samburu County). METHODS: Eighty-nine patients (17.9% F; 31.7 ± 18.9 yrs) who underwent intramedullary nail treatment for femur or tibia fractures were enrolled in this study. Both S&S [evaluated by a goal attainment scale (GAS)] and x-ray (evaluated by REBORNE, Bone Healing Score) were performed at 6 and 24 weeks, postoperatively. An acceptable margin for satisfactory S&S GAS scores was determined by assessing its validity, reliability, and sensitivity. RESULTS: S&S GAS scores increased over time: 80.2% of patients performed a satisfactory S&S at the 24-weeks follow-up with a complete BH. A high correlation between S&S GAS and REBORNE at the 6- and 24- weeks’ timepoint was found. Facial expression correlated partially with BH. The S&S proved to be accurate at correctly depicting the BH process (75% area fell under the Receiver Operator Curve). CONCLUSION: The S&S provides a possible substitution for bone x-ray during BH assessment. The potential to remotely follow up the BH is certainly appealing in low- and middle-income countries, but also in high-income countries; as was recently observed with the Covid-19 pandemic when access to a hospital is not conceivable.