Patellofemoral (PF) complications are among the most frequently observed adverse events after total knee arthroplasty (TKA). It has been reported that PF complications after TKA include decreasing knee range of motion, anterior knee pain, quadriceps and patellar-tendon rupture, patellar subluxation, and partial abrasion and loosening of the patellar component. Although recent improvements in surgical technique and prosthetic design have decreased these complications, the percentage of patients who have a revision TKA for PF complications still ranged up to 6.6% to 12%. For the present study, we hypothesized that the alignment of the femoral component is correlated with PF contact stress. The purpose of this study was to investigate the relationship between femoral component alignment and PF contact stress in vivo, using a pressure sensor in patients who had favorable extension-flexion gap balance during TKA. Thirty knees with medial compartment osteoarthritis that underwent posterior stabilized mobile-bearing TKA using identical prostheses (PFC Sigma RPF; Depuy, Warsaw, IN, USA) by a single surgeon (TM) with modified gap technique under a computed tomography (CT)-based navigation system (Vector Vision 1.61; Brain Lab, Heimstetten, Germany) were evaluated. PF contact stress was measured intraoperatively and compared with the alignment of the femoral component including intraoperative navigation data concerning medial shift of the patella and lateral tilt of the patella, postoperative coronal femoral component angle (alpha angle), postoperative sagittal femoral component angle (gamma angle), postoperative condylar twist angle (CTA), postoperative lateral condylar lift-off angle, and postoperative mechanical femoral component angle (mFCA). In addition, postoperative Insall-Salvati ratio (I-S ratio) was measured by dividing the length of patellar tendon by the greatest diagonal length of the patella.Introduction
Methods
Total hip arthroplasty (THA) markedly improves pain, gait, and activities of daily living for most patients with osteoarthritis. However, pelvic osteotomy has been recommended for young and active patients with hip dysplasia, because THA in that population is associated with high rates of revision THA. The rotational acetabular osteotomy (RAO) of Ninomiya and Tagawa, and the eccentric rotational acetabular osteotomy of Hasegawa for hip dysplasia reportedly are successful in young and active patients. However, even after the surgery of RAO, osteoarthritis developed in some cases and leaded to the conversion to THA. The differences of bone quality of acetabulum have been reported between at the surgery of THA after RAO and at the surgery of primary THA. We should not discuss the results of these two THA equally. The purpose of this study is to report the results of THA after RAO. We retrospectively reviewed 33 patients (37 hips) treated by total hip arthroplasty after rotational acetabular osteotomy between 1992 and 2012. Five cases were performed RAO with valgus osteotomy. At the time of THA surgery, the overall mean age of the patients was 57.5 years (range, 39–72 years). The average of follow-up period was 7.0 years (range, 8–258 months). One surgeon (TT) evaluated the hips clinically using the Japanese Orthopaedics Association (JOA) score. The radiographic measurements were performed by the other physician (JY) blinded to the clinical scores. Radiographical examination was performed using AP X-ray. We evaluated the presence of osteolysis and loosening of the implants. We evaluated the stability of stem implants using Engh classification and of cup implants using Hodgkinson classification.[Introduction]
[Patients and Methods]
Loss of bone stock is a technically challenging problem in revision total hip arthroplasty (RevisionTHA). Impaction bone grafting (IBG) is an attractive biological method of reconstruction. We performed acetabular revisions using IBG and cemented cup in patients with failed hip prosthesis and large defects. The purpose is to report the short term results of revision THA with using IBG. We retrospectively reviewed 19 patients/19 hips revised for aseptic loosening of a cemented or uncemented cup, three male/16 female, mean 65.5 ± 8.8 years old (43–75). Mean follow up time is 18 months. Classification of acetabular defects according to A.A.O.S classification were Type I; 5 hips, Type III; 13 hips and Type V; 1 hip. Before impacting the morselized bone allograft and cement, segmental acetabular defects were reconstructed with metallic meshes screwed to the bone bed. Morselized allograft bone chips (diameter 7ï¼ 10 mm) were impacted forcefully. All-polyethylene cups (Stryker, Crossfire) were cemented. Clinical examination was performed using Japanese Orthopaedic Association (JOA) score. Radiographic examination was performed using AP radiographs. We measured the inclination cup angle, the distance of superior migration, the presence of loosening of the implanted cup, 4 weeks postoperatively and at the last follow up. Loosening was defined as migration distance was more than 5 mm in any direction.Introduction
Patients & Methods
