Purpose was to evaluate the incidence of complication in lower limb reconstructions with modular prostheses comparing cemented versus uncemented stems in two different orthopedic tumor Centers.

Methods: retrospective analysis of implant survival, complications and functional results assessed according to MSTS system of the Rizzoli and Moffitt series of modular megaprosthesis in lower limb.

From 2002 and 2007, 238 modular prostheses of same design with a rotating hinge knee, were implanted in the lower limb as primary reconstruction in these two Centers. In 130 cases the prosthesis was implanted with cemented stems and in 108 cases with uncemented stems. Sites included: 120 distal femur, 61 proximal femur, 46 proximal tibia, 10 total femur and in 1 case both distal femur and proximal tibia. Histologic diagnoses included: 89 osteosarcoma, 13 Ewing sarcoma, 21 chondrosarcoma, 19 sarcoma, 55 metastasis, 17 TGC, 7 MFH, 11 other diagnoses and 6 non oncologic cases.

Major prostheses-related complications were analysed and functional results according to Muscolo Skeletal Tumor Society system, at a mean follow up of 2.03 yrs. Also a statistical evaluation with Kaplan Meier curves, a comparative statistical analysis with Wilcoxon test and multivariate Cox regression analysis were performed.

Results: Outcome in 223 evaluated oncologic pts, showed: 121 pts continuously disease free, 26 NED after treatment of relapse, 54 AWD, 16 DWD. Margins were wide in 94.3% (214/227 pts) of evaluated pts. Complications causing implants failure were: infections in 20/238 (8.41%), aseptic loosening in 7/238 (2.95%). No breakages of prosthetic components were observed.

Infections occurred at mean time of 1.3 yrs, sites included: 9 distal femurs, 4 proximal femurs, 5 proximal tibias, 2 total femurs. Aseptic loosening occurred at mean time of 2.3 yrs, sites included: 3 proximal tibias, 2 distal femurs, 2 proximal femurs. Rate of aseptic loosening was higher for cemented stems 5/130 (3.85%) vs uncemented 2/108 (1.85%). This difference is not statistically significant. Infection rate was 10% (13/130) for cemented stems and 6.5% (7/108) for uncemented stems. This difference is statistically significant at comparison of survival curves logrank test. Average MSTS function score was 83.5%. Multivariate Cox regression analysis showed that the significant factor favourable reluted with lower incidence of complications was the use of uncemented stems.

Conclusions: lower limb modular prostheses with both cemented and uncemented stems gave good results and a low complication rate. Better results were observed with uncemented stems and statistically confirmed, but this needs to be further investigate in a future study at long term.

Introduction: Core decompression has historically been used during the early stages of osteonecrosis of the ankle as a treatment method to decrease pain and defer the eventual collapse of the joint. Originally, this procedure was described using large diameter trocars. The multiple locations of the lesions (such as the distal tibia and fibula, the talar dome, the calcaneus, and/or the metatarsals) and the relative small affected bones (compared to the femoral head and distal femur) make this procedure technically difficult. The investigators report on the treatment of osteonecrosis of the ankle with a new technique using multiple small percutaneous 3-mm perforations.

Methods: Between September, 2002 and May, 2004, the senior author treated 44 symptomatic ankles affected with osteonecrosis using the multiple perforation technique. The series included 31 patients (23 women, 8 men) who had a mean age at the time of surgery of 42 years (range, 17 to 61 years). All the procedures were performed using a 3-millimeter Steinman pin technique. Radiographic outcome was assessed during post-operative clinical visits using plain x-rays and magnetic resonance imaging. Clinical outcome was assessed postoperatively using the AOFAS (American Orthopaedic Foot and Ankle Society) score. Progression of the disease (defined as evidence of subchondral collapse or AOFAS score < =80 points) was correlated with demographic variables such as associated risk factors, prior surgical procedures, size, and location of the lesions.

Results: Ankle arthrodesis was avoided in 93% of the cases (41 of 44 ankles) at a mean follow-up of 3.6 years (range, 2 to 5 years). Forty of 44 ankles (91%) had a successful clinical outcome (AOFAS score ≥ 80 points). The AOFAS score for the entire series increased from a preoperative mean of 41 points (range, 34 to 55 points) to a postoperative mean of 88 points (range, 51 to 100 points). The AOFAS score for the series excluding the three ankles that required arthrodesis increased from a preoperative mean of 41 points to 91 points postoperatively. The three cases that required ankle arthrodesis presented initially with osteonecrosis of multiple bones about the ankle (talus, calcaneus, distal tibia and fibula) and two of these cases had HIV as an associated risk factor for osteonecrosis. All but 8 patients presented signs and symptoms of osteonecrosis in other joints (hip, knee, shoulder) and this had a negative correlation with outcome. There were no complications from the procedures, which were all performed as outpatient surgeries.

Discussion: The percutaneous perforations technique appears to be a low-morbidity method of relieving symptoms and deferring ankle arthrodesis (or other invasive procedures) in patients with symptomatic osteonecrotic ankles. The authors believe that these results support the need for a multicenter-randomized study comparing minimally invasive treatment options for osteonecrosis.

Introduction: Osteonecrosis of the knee occurs with approximately 10% of the incidence of osteonecrosis of the hip. Core decompression is a minimally invasive technique which can potentially forestall bony collapse and thus avoid the need for joint arthroplasty. The purpose of this study was to evaluate the efficacy of a new minimally invasive approach using a small diameter Steinman pin to perform core decompression of the knee.

Materials and Methods: Between September 5, 2000 and May 30, 2003, the senior author performed 55 core decompressions of the knee in 39 patients with symptomatic osteonecrosis of the knee. All procedures were performed using the small-bit drilling technique. There were 32 women and 7 men who had a mean age of 43 years (range, 18 to 52 years). Radiographic and clinical outcomes were assessed during post-operative clinical visits, with persistent pain, loss of joint space, or progression to total knee replacement considered failures.

Results: There were excellent or good outcomes in 45 knees (82%) at a mean three year follow-up (range, 2 to 5 years). Four patients had symptomatic knees that led to total knee arthroplasty. There were no complications from the procedures which were all performed as out-patient surgery.

Discussion: The percutaneous drilling technique appears to be a low-morbidity method of relieving symptoms in patients with symptomatic knees from osteonecrosis. These short-term results are encouraging for this difficult to treat disease.

Introduction: Metal-on-metal resurfacing is a type of total hip arthroplasty that is conservative on the femoral side. It is controversial whether this procedure should be used in patients with avascular necrosis where the femoral resurfacing component is cemented on dead bone. This study analyzed the clinical and radiographic outcome of patients with avascular necrosis treated with metal-on-metal total hip resurfacing arthroplasty.

Materials and Methods: Thirty-seven patients (41 hips) treated with late-stage avascular necrosis of the hip with a metal-on-metal resurfacing hip arthroplasty were studied. There were 27 men and 10 women who had a mean age of 40 years (range, 16 to 62 years). Patients were followed both clinically and radiographically for a minimum of two years (mean of 3 years).

Results: Overall, there were good and excellent clinical outcomes in 38 hips (93%). Fair results were found in three patients who had excessive heterotopic bone (2 hips) and persistent groin pain (1 hip). There were no cases of component loosening. Radiographic zonal analysis revealed no evidence of impending failure or progressive radiolucencies.

Discussion: Excellent short-term results were found with metal-on-metal total hip resurfacing in this difficult patient population. The authors await long-term results to see if these early excellent results are maintained.

Introduction: The results of total hip arthroplasty in patients with avascular necrosis of the hip have been variable. This study analyzed the clinical and radiographic outcome of young patients (mean age of 39 years) treated with a proximally hydroxyapatite-coated tapered stem.

Materials and Methods: Sixty-seven patients (84 hips) treated with late-stage avascular necrosis of the hip with a proximally hydroxyapatite-coated tapered stem as part of their total hip arthroplasty was studied. There were 41 men and 26 women who had a mean age of 39 years (range, 18 to 80 years). Patients were followed both clinically and radiographically for a minimum of two years (mean of 3 years).

Results: Overall, there were good and excellent clinical outcomes in 78 hips (93%). Fair results were found in five patients with persistent pain. There was only one stem loosening (obese patient with SLE). Radiographic zonal analysis revealed no evidence of impending failure or progressive radiolucencies.

Discussion: Excellent short-term results were found with total hip arthroplasty in this difficult patient population. The proximally hydroxyapatite-coated tapered stem utilized in this study was useful in patients with avascular necrosis of the hip.