Midterm outcomes of titanium modular femoral necks in total hip arthroplasty

Abstract

Background: Modular femoral necks present surgical and biomechanical advantages in total hip arthroplasty (THA), but their benefits remain controversial due to risks of corrosion and fracture at the additional junction. This study aimed to report 10-year survival and clinical outcomes of a titanium femoral stem with a titanium modular neck in consecutive series. Methods:The authors reviewed the records of 97 patients (99 THAs) using uncemented modular stem and ceramic-on-ceramic acetabular components. Patients were evaluated at minimum follow-up of 5 years using the Harris Hip Score (HHS) and Postel Merle-D'Aubigné score (PMA). Survival was calculated using the Kaplan-Meier (KM) method with any reoperation or revision as endpoint.Results: From the original cohort, 14 patients died, 6 were lost to follow-up, and 5 had revision operations with exchange of the femoral stem. The KM survival at 10 years was 94.2% (CI, 86.5-97.5). Clinical assessment was performed on 67 of the 72 patients (69 of the 74 hips) presently living with their original THA components. At mean follow-up of 9.4±1.0 years (median, 10; range, 5-11), the HHS was 93.6±8.2 and the PMA score 17.0±1.6. The X-rays revealed no signs of adverse reactions or bone loss. Conclusions:The uncemented titanium hip stem with modular titanium neck provided a satisfactory 10-year survival and clinical outcomes. Neck modularity enabled restoration of patient-specific femoral offset and limb length thanks to five possible neck configurations, though greater follow up is required to confirm the long-term benefits and safety of this design concept.

Modular neck stems in total hip arthroplasty: current concepts

“…7–98.6). Collet et al, 38 in their series, registered a mean postoperative HHS of 93.6±8.2 at a mean follow-up of 9.4 years, which was greater than the results reported by several other authors. 26 , 30 , 33 The MAPS score summarized in Table 3 improved from an average preoperative score of 10 to a postoperative mean score of 17.5 (15–18).…”

“…As described by different authors 5 , 10 , 38 the modularity was effective in restoring offset and leg length, and these confer stability with a good mid to long-term follow-up. Traina et al 49 reported that MN prostheses allow the restoration of femoral offset, abductors moment arm, leg length and joint kinematics especially in critical cases of THA, such as high-grade dysplasia.…”

“…Montalti et al 23 with the longest follow-up registered (15 years) presented a survival rate of 90.5%, with only two cases of aseptic loosening out of 80 implants. Also Collet et al 38 with a rate of 94.2%, with any revision or reoperation as endpoint, registered a good survival of the stems used. Cossetto et al 29 reported 10-year KM survival of 96% for the MBA stem; Blakey et al 33 reported five-year KM survival of 97.5% for the ANCA-Fit stem; and Silverton et al 26 reported eight-year KM survival of 89.4% for the uncemented modular Profemur® Z stem.…”

Dual Modular Titanium Alloy Femoral Stem Failure Mechanisms and Suggested Clinical Approaches

“…In recent years, some studies have reported satisfactory results using dual modular stems in primary THAs [ 106 , 107 , 108 ]. Specific dual modular stems offer a better reconstruction of hips that deviate from standard anatomy when compared to a monoblock arthroplasty system with different offset options [ 109 ].…”

Mid-term outcomes of titanium modular neck femoral stems in revision total hip arthroplasty

“…Modular stems have been studied by many authors as they allow intraoperative adjustments of femoral neck anteversion, offset, and limb length to better restore muscle tensions and hip biomechanics (5)(6)(7)(8). In primary THA, several modular stems have been associated with corrosion or fracture at their junctions, though models made of titanium bodies and necks seem to obviate these problems, and grant satisfactory mid-term survival and excellent clinical outcomes at 10 years (9).…”