Total hip arthroplasty (THA) outcome in patients with osteonecrosis of the femoral head ONFH) are excellent, however, there is controversy when compared with those in patients with osteoarthritis (OA). Reduced mineralization capacity of osteoblasts of the proximal femur in patients with ONFH could affect implant fixation.

We asked if THA fixation in patients with ONFH is worse than in those with OA.

We carried out a prospective comparative case (OA)-control (ONFH) study of patients undergoing THA at our hospital between 2017 and 2019. The minimum follow-up was 2 years. Inclusion criteria were patients with uncemented THA, younger than 70 years old, a Dorr femoral type C and idiopathic ONFH. We compared the clinical (Merlé D'Aubigné-Postel score) and radiological results related with implant positioning and fixation. Engh criteria and subsidence were assessed at the immediate postoperative, 12 weeks, 6 months, 12 months and yearly. Osteoblastic activity was determined by mineralization assay on primary cultures of osteoblasts isolated from trabecular bone samples collected from the intertrochanteric area obtained during surgery.

Group 1 (ONFH) included 18 patients and group 2 (OA), 22. Average age was 55.9 years old in group 1 and 61.3 in group 2. (p=0.08). There were no differences related with sex, Dorr femoral type or femoral filling. The mean clinical outcome score was 17.1 in group 1 and 16.5 in group 2 (p=0.03). There were no cases of dislocation, infection, or revision surgery in this series. There were 5 cases (28%) of femoral stem subsidence greater than 3mm within 6 first months in group 1 and 1 case (4.5%) in group 2 (p=0.05).

Although there were no significant differences related to clinical results, bone fixation was slower, and a greater subsidence was observed in patients with ONFH. Greater femoral stem subsidence was associated with a lower capacity for mineral nodule formation in cultured osteoblasts. The surgical technique could influence THA outcome in patients with reduced mineralization capacity of osteoblasts.

Results in patients undergoing total hip arthroplasty (THA) for femoral head osteonecrosis (ON) when compared with primary osteoarthritis (OA) are controversial. Different factors like age, THA type or surgical technique may affect outcome. We hypothesized that patients with ON had an increased revision rate compared with OA. We analysed clinical outcome, estimated the survival rate for revision surgery, and their possible risk factors, in two groups of patients.

In this retrospective cohort analysis of our prospective database, we assessed 2464 primary THAs implanted between 1989 and 2017. Patients with OA were included in group 1, 2090 hips; and patients with ON in group 2, 374 hips. In group 2 there were more men (p<0.001), patients younger than 60 years old (p<0.001) and with greater physical activity (p<0.001). Patients with lumbar OA (p<0.001) and a radiological acetabular shape type B according to Dorr (p<0.001) were more frequent in group 1. Clinical outcome was assessed according to the Harris Hip Score and radiological analysis included postoperative acetabular and femoral component position and hip reconstruction. Kaplan-Meier survivorship analysis was used to estimate the cumulative probability of not having revision surgery for different reasons. Univariate and multivariate Cox regression models were used to assess risk factors for revision surgery.

Clinical improvement was better in the ON at all intervals. There were 90 hips revised, 68 due to loosening or wear, 52 (2.5%) in group 1, and 16 (4.3%) in group 2. Overall, the survival rate for revision surgery for any cause at 22 years was 88.0 % (95% CI, 82-94) in group 1 and 84.1% (95% CI, 69 – 99) in group 2 (p=0.019). Multivariate regression analysis showed that hips with conventional polyethylene (PE), compared with highly-cross linked PEs or ceramic-on-ceramic bearings, (p=0.01, Hazard Ratio (HR): 2.12, 95% CI 1.15-3.92), and cups outside the Lewinnek´s safe zone had a higher risk for revision surgery (p<0.001, HR: 2.57, 95% CI 1.69-3.91).

Modern highly-cross linked PEs and ceramic-on-ceramic bearings use, and a proper surgical technique improved revision rate in patients undergoing THA due to ON compared with OA.

Introduction and purpose: There still remain controversies with regard to knee replacements, such as the preservation or replacement of the patellar surface. Although numerous studies have compared the clinical results of the two procedures, there have been few long-term radiological follow-up studies of the non-resurfaced patella. Our purpose is to assess this follow-up and determine the relation to clinical pain pictures of patellar origin.

Materials and methods: We carried out a clinical and radiological study of 74 PFC modular arthroplasties without patellar resurfacing with a mean follow-up of 10 years (range: 9–12 years). We measured the size and height of the patella, Wiberg classification, degree of patellar sclerosis, patellar excursion and presence and size of bone spurs. We carried out an exhaustive examination of the extensor apparatus. We related the radiological data to the clinical picture of the patella.

Results: We observed a tendency toward reduced titlting, increased height and width and diminished patellar thickness. None of these variations was statistically related to the onset of patellar pain or sustained pain.

Conclusions: Radiological variations of the non-resurfaced patella in total knee arthroplasty do not result in patellar clinical pictures.

Introduction and Objectives: Extraskeletal osseous sarcomas are very rare high-grade tumours. They include osteosarcoma, chondrosarcoma, and Ewing’s soft tissue sarcoma and their respective variants. We present a retrospective study of 25 cases covering the period from December 2002 to January 2003.

Materials and Methods: This study of 25 cases shows that this heterogeneous group of soft tissue sarcomas primarily affects adults (mean age 50.68; range 17 to 70 years). The thigh (36.60%) and the elbow-forearm (18.18%) are the most common locations for these tumours. In these cases, 14 chondrosarcomas, 8 osteosarcomas, and 3 Ewing’s sarcomas were diagnosed. Mean follow-up time was 48.9 months with a range of 16 to 197 months. There were 16 surgeries performed with wide or compartmental margins, while in the 5 remaining cases, amputations were performed, and one case of Ewing’s sarcoma of the pelvis was treated by means of chemotherapy and radiation therapy, as it was considered non-resectable. All cases of osteosarcoma and Ewing’s sarcoma were treated by means of pre- and postoperative chemotherapy and postoperative radiation therapy.

Results: The postoperative duration of symptoms ranged from 2 weeks to 6 years with a mean of 6 months. Local recurrence following surgery with wide or compartmental margens occurred in 8 cases, representing 35.45% (3 chondrosarcomas, 4 osteosarcomas, and 1 Ewing’s sarcoma). The total number of cases surviving without recurrence is 14 (63.6%), surviving cases with one or more recurrences is 5 (22.72%), one case is alive with metastasis (4.59%), and 3 sarcomas (2 ulcerated upon admission) had disseminated and the patients died (10.05%).

Discussion and Conclusions: All these tumours were high-grade sarcomas. The most common metastatic localizations were lungs, regional ganglia, and skeleton. The recommended treatment is surgery with wide or compartmental margins, if possible in the early stages, in conjunction with chemotherapy and radiation therapy. The worst prognosis corresponds to the osteosarcoma.

Introduction and Objectives: The goal of cementless endoprosthetic hip surgery is to improve bone attachment. The gold standard method for evaluating periprosthetic bone characteristics is densitometry. This study was designed to compare periprosthetic bone mass in 2 groups of patients: less than 3 years and more than 3 years after implantation.

Materials and Methods: A total of 195 type ABG-II total hip prostheses were implanted from November 1997 to March 2003. This implant is a hemispheric cup coated with hydroxyapatite, which can additionally be anchored with screws and a short anatomic stem with metaphyseal fixation. DeLee and Gruen zones were analysed.

Results: During the study period, patients with implants less than 3 years old showed no significant changes in bone mineral density around the stem or the cup. In area 7, a statistically significant reduction was noted after 3 years (0.5218g/cm3, p< 0.001). In Gruen’s zones 3 and 4 a non-significant gain was observed after 3 years (1.1618g/cm3).

Discussion and Conclusions: In cup studies, a statistically insignificant increase in density was observed in zone I after 3 years. Noteworthy findings included a loss of function in DeLee zone III and Gruen zones 1 and 7, which has not yet had clinical consequences (at a maximum 6 year follow-up time).

Introduction and Objectives: Periprosthetic fractures are a common phenomenon in revision surgery and following trauma. Treatment strategies range from replacement with a larger stem, metal plates with Dall-Miles wires, and Partridge straps. Our objective is to evaluate the clinical use of Partridge osteosynthesis in periprosthetic femoral fractures.

Materials and Methods: In a period of 6 years (1997–2003), 45 patients presenting with femoral fractures with a hip prosthesis were treated with the Partridge system using nylon material for cerclage and flexible nylon plates (Stryker-Howmedica). Of these, 20 were localised proximal to the tip of the prosthesis (Whittaker Type I), 12 on the tip (Type II), and 13 distal to the tip of the prosthesis (Type III). The study group consisted of 25 females and 20 males, with a mean age of 79.5 years. Mean time between implantation and fracture was 4.5 years. In 78% of the patients (35 of 45), surgery was performed within 48 hours. Open reduction of the fracture was performed, and 6–8 nylon straps were used in most cases. Partridge plates were used in 5 cases. Mean surgical time was 55 minutes, with a mean blood loss volume of 500 milliliters.

Results: There were minor recovery complications in 8 patients (12.6%). There were no deep wound infections. Of the 45 patients, 60% regained their pre-fracture level of function within 6 months. Mean hospital stay duration was 19 days, and 93% of the fractures consolidated with an exuberant callus within the one-year follow-up period. A higher level of care was required by 25% of patients.

Discussion and Conclusions: This simple method of osteosynthesis is indicated for rapid recovery following stabilisation of a periprosthetic femoral fracture. Even with a mobilised prosthesis, the fracture often consolidates with an abundant callus, and the patient is then able to move.