BackgroundMetastatic bone disease involving the acetabulum is a debilitating condition causing significant pain and disability for patients. Many methods of reconstruction have been described for treating Harrington class II and III lesions with different results and complications. Our objectives were to report functional results, implant survival and complications following reconstruction for Harrington class II and III periacetabular metastases by using anti-protusio cages, screws and joint replacement.MethodsWe reviewed 22 patients undergoing acetabular reconstruction for metastatic disease. There were 5 Harrington class II and 17 class III lesions. Intralesional curettage, multiple screws and cemented total hip replacement were performed in all patients. Anti-protusio cages were used in 19 hips. No Steinmann pins were used. Sixteen patients died at a median survival time of 12 months (range, 4 to 28 months) after surgery. Six patients were alive at last follow-up at a median of 8 months (range, 3 to 15 months).ResultsPostoperatively, the average ECOG score was improved from 3.1 to 1.7 and Visual Analog Scale was improved from 8.4 to 2.2. One patient developed hip dislocation and one patient developed superficial infection. The mean Musculoskeletal Tumor Society (MSTS) functional score was 70 (range, 27 to 87). There was no prosthetic loosening or revision. Twenty patients were able to walk. Eight patients became community ambulators, twelve became household ambulators and two were bed-bound.ConclusionsGood functional outcome and better ambulation could be expected following class II and III periacetabular reconstruction using anti-protusio cages, screws and cemented hip replacement. Few complications were noted and manageable. Although most of these patients with metastatic disease had limited life expectancies, their quality of life would be improved with appropriate patient selection and surgical reconstruction.

Purpose: Septic arthritis and osteomyelitis due to Serratia marcescens are very rare, with only a few cases reported in the literature. This report presents a case of septic arthritis and osteomyelitis of the hip joint caused by Serratia marcescens after COVID-19. Methods: A case report of a patient who had septic arthritis of Serratia marcescens was reported. A review of literature of the bone and joint infection caused by Serratia marcescens was also done.  Results: The patient was successfully treated with an open arthrotomy, debridement, and intravenous antibiotics. After 9 months, the patient showed good functional outcomes, with no signs of recurrent infection. Conclusions: Septic arthritis caused by Serratia marcescens is a rare condition. Early diagnosis and urgent surgical debridement are key factors for success.

Fibrous tether at the distal femur is a rare condition that causes angular deformity of the lower extremity; only 18 cases have been reported previously. We report the case of a 2-year-old boy presenting with unilateral genu valgus. The patient had a subsequent lateral patellar dislocation, 1 year after surgical correction. A second surgery was performed to correct this patellar dislocation. Intraoperative finding indicated contracted lateral patellar retinaculum. To the best of our knowledge, this is the first report of such a finding. The natural history is still not understood. At the 6-month-follow-up visit, the patient still has good results without recurrent patellar dislocation or angular deformity. We also review the literature in terms of proper treatment and results of treatment.