Originally introduced in 1997, porous tantalum is an attractive alternative metal for orthopaedic implants because of its unique mechanical properties. Porous tantalum has been used in numerous types of orthopaedic implants, including acetabular cups in total hip arthroplasty. The early clinical results from porous tantalum acetabular cups have been promising. The purpose of this study was to evaluate the presence of bone ingrowth and the incidence of osteolytic lesions in the acetabular cup -at 10 year follow up – in patients who had a total hip arthroplasty with a monoblock porous tantalum acetabular cup. 50 consecutive patients underwent a total hip arthroplasty with a monoblock porous tantalum acetabular component. All patients had computed tomography at an average of 10 years of follow-up. The computed tomography scan used a standard, validated protocol to evaluate bony ingrowth in the cup and for the presence of osteolysis. The computed tomographic scans showed evidence of extensive bony ingrowth, and no evidence of osteolysis. This study reports the 10-year results of a monoblock porous tantalum acetabular cup. This is the first study to evaluate a porous tantalum acetabular cup with the use of computed tomography. These results show that a porous tantalum monoblock cup has excellent bony ingrowth and no evidence osteolysis at 10 year follow-up. These results suggest that porous tantalum is an attractive material for implantation in young, active patients.
When compared with traditional techniques, computer-assisted total knee arthroplasty (TKA) has been shown to allow more accurate coronal alignment of the implants with fewer “outliers.” Most navigation systems in computer-assisted TKA utilize rigidly-fixed trackers placed on both the femur and tibia, a computer workstation, and navigation software to determine the mechanical axis of the extremity intraoperatively, in real time. The purpose of this study was to report the initial experience of a single surgeon with a novel navigation system. This system utilizes a “pinless” technique using trackers that are mounted at the articular surface of the knee instead of being fixed to the femur and tibia. Sixty-Six consecutive TKAs were performed using a novel “pinless” navigation system by a single surgeon. At 4 weeks post-operatively, coronal alignment was assessed with long-standing AP radiographs. The alignment measurements were then compared to historical controls. The average alignment in the coronal plane was 1.73° +/−1.50° deviation from neutral alignment. Variance was 2.26°. The c onfidence interval constructed with an alpha value of.05 was (1.50°, 2.40°). Five knees had a coronal alignment greater than 3° from neutral. Of these five, three had an ipsilateral total hip replacement, and 2 were morbidly obese. There were no pin site infections nor pin site fractures. There was 1 late hematogenous infection. This study reports an initial single-surgeon experience of a novel “pinless” navigation technique for TKA. The technique in this study is a novel and safe method to reconstruct a neutral mechanical axis, as it avoids the morbidity of the application of navigation tracking pins and therefore enhances patient safety.
