ResumoLuxação intra-articular da patela é uma afecção incomum, podendo ocorrer deslocamento no plano horizontal ou vertical; pode se associar com lesão/ruptura do tendão do quadríceps, total ou parcial, com lesão osteocondral ou dos ligamentos colaterais. Fatores de risco são: frouxidão ligamentar, hipermobilidade patelar, patela alta e displasia troclear, e é mais comum em jovens, podendo necessitar de redução cruenta. Casos de luxação intra-articular da patela são eventos raros, sendo necessários uma suspeição diagnóstica e um manejo diferenciado. O objetivo deste trabalho é relatar um caso raro de luxação intra-articular da patela, assim como seu quadro clínico, diagnóstico, conduta e revisão da literatura.

Objective  To prospectively analyze the radiographic variables of lumbosacral sagittal balance in the pre- and postoperative period of patients submitted to total hip arthroplasty (THA). Methods  A prospective, observational, comparative study that evaluated pre- and postoperative radiographic parameters of 71 patients, submitted to 72 total hip arthroplasties in a 3-year period (2014–2017) for primary coxarthrosis, of whom 28 performed late postoperative control (6 months) through the Surgimap Spine software (Surgimap, New York, NY, USA). Statistical analysis was performed using the Student t-test, the analysis of covariance (ANCOVA) model, and the Kolmogorov-Smirnov test. The data were analyzed using the IBM SPSS Statistics for Windows, Version 20.0 (IBM Corp., Armonk, NY, USA). A p-value < 0.05 indicated statistical significance. Results  A total of 72 cases, presenting a mean age of 57.9 years old, predominantly females (60.6%) and patients > 50 years old (71.8%). There was an overall decrease in lumbar lordosis values in the immediate postoperative period, without major global changes in late evolution. It was found that patients with a pelvic incidence ≥ 60° tended to have their other sagittal balance parameters elevated. Conclusion  There was no significant difference between the radiographic variables of sagittal lumbopelvic balance in the evaluated periods. Lumbar lordosis and pelvic incidence were the main modifying factors. Improvement of low back pain after THA, without changes in parameters, suggests different pathology mechanisms still to be clarified.