In the News
Modular femoral heads have been used successfully for many years in total hip arthroplasty. Few complications have been reported for the modular Morse taper connection between the femoral head and trunnion of the stem in metal-on-polyethylene bearings. Although there has always been some concern over the potential for fretting, corrosion, and generation of particulate debris at the modular junction, this was not considered a significant clinical problem. More recently, concern has increased because fretting and corrosive debris have resulted in rare cases of pain, adverse local tissue reaction, pseudotumor, and osteolysis. Larger femoral heads, which have gained popularity in total hip arthroplasty, are suspected to increase the potential for local and systemic complications of fretting, corrosion, and generation of metal ions because of greater torque at the modular junction. A less common complication is dissociation of the modular femoral heads. Morse taper dissociation has been reported in the literature, mainly in association with a traumatic event, such as closed reduction of a dislocation or fatigue fracture of the femoral neck of a prosthesis. This report describes 3 cases of spontaneous dissociation of the modular prosthetic femoral head from the trunnion of the same tapered titanium stem because of fretting and wear of the Morse taper in a metal-on-polyethylene bearing. Continued clinical and scientific research on Morse taper junctions is warranted to identify and prioritize implant and surgical factors that lead to this and other types of trunnion failure to minimize complications associated with Morse taper junctions as hip implants and surgical techniques continue to evolve.
Justin LaReau, MD. Hinsdale (Ill.) Orthopaedics. Dr. LaReau has more than 10 years of surgical experience. He specializes in joint preservation and reconstruction of the hip and knee. Dr. LaReau is also an instructor for the American Academy of Orthopedic Surgeons.
Purpose: To detail our early experience using concomitant hip arthroscopy and periacetabular osteotomy (PAO) for the treatment of acetabular dysplasia.
Accuracy of Component Positioning in 1980 Total Hip Arthroplasties: A Comparative Analysis by Surgical Technique and Mode of Guidance.
The purpose of this multi-surgeon study was to assess and compare the accuracy of acetabular component placement, leg length discrepancy (LLD), and global offset difference (GOD) between six different surgical techniques and modes of guidance in total hip arthroplasty (THA). A total of 1980 THAs met inclusion criteria. Robotic- and navigation-guided techniques were more consistent than other techniques in placing the acetabular cup into Lewinnek’s safe zone (P<0.005 and P<0.05, respectively). Robotic-guided surgery was more consistent than other techniques in placing the acetabular component within Callanan's safe zone (P<0.005). No statistically significant differences were found between groups in the frequency of patients with excessive LLD. Clinically significant differences between groups were not found in the frequency of patients with excessive GOD.
Mixed femoroacetabular impingement (FAI) is typically managed with both femoral and acetabular rim osteoplasties, but it has not been reported if the rim osteoplasty is always required. We hypothesized that mixed FAI managed by femoral or combined femoral and acetabular osteoplasties will both attain satisfactory clinical results, provided intraoperative impingement-free functional motion is attained.