A Role for Modern Primary Cementless Femoral Stems in Revision Hip Arthroplasty

Outcomes of Primary Cementless Femoral Stems Used in Revision Hip Arthroplasty

INTRODUCTION

An abundance of literature exists assessing outcomes of revision THA using diaphyseal engaging stems; however, there is little research into the use of primary-style femoral stems in revision THA. Primary stems may have benefits including cost reduction, maintenance of proximal bone stock, and ease of potential future reconstructions. The purpose of this study was to evaluate the aseptic survival rate of revision THAs using primary femoral stems.

METHODS

A review of our registry was performed to identify patients from 2010 to 2020 who underwent all-cause revision THA utilizing a primary metaphyseal-engaging stem for femoral reconstruction. Patients who had a history of previous revision THA or those treated with cement or bone graft augmentation were excluded. There were seven patients excluded due to a lack of two-year follow-up. Implant survival, complications requiring revision surgery, and ambulatory status at final follow-up were documented. There were 78 patients who met the final inclusion criteria. The mean follow-up was 5.2 years (range, 2.0 to 10.0).

RESULTS

The most common indications for index revision were aseptic loosening (44%) or infection (34%). Pre-revision Paprosky classification of the femur was Type I in 41 patients (52%), Type II in 37 patients (47%), and Type 3A in one patient (1%). Overall, 13 patients (16.5%) required re-revision, five for periprosthetic fracture, six for instability, and two for recurrent infection. Of those, seven of 13 required femoral component revision. When excluding recurrent infections, the aseptic femoral-component survivorship for the cohort was 94%. There were three patients who sustained a fracture requiring stem re-revision. A Vancouver B1 fracture was sustained > two years postoperatively, and two Vancouver B2 fractures were sustained within six months postoperatively. There were no femoral re-revisions for aseptic loosening.

CONCLUSION

Primary metaphyseal-engaging femoral stems provide reliable fixation during revision THA in patients who have preserved proximal metaphyseal bone with similar complication rates to those previously reported in the literature for revision THA.

Cementless Femoral Component in Revision Hip Arthroplasty: A Registry Comparative Study Between Primary and Revision Stems

INTRODUCTION

Femoral component choice in revision hip arthroplasty is debated. An arthroplasty registry study was designed to compare the survival rates of revision hip arthroplasties performed for femoral component failure using noncemented primary stems or noncemented revision stems, aiming to assess (1) the survival rates of primary and revision stems and (2) the survival rates of primary and revision stems, in single-taper and modular versions.

METHODS

In a regional arthroplasty registry, 5,186 revision surgeries of femoral component using noncemented stems performed on residing patients were identified: 1,127 primary stems (21.7%) and 4,069 (78.3%) revision stems. Implants were additionally categorized according to modularity. The cohorts differed for demographic and implant-related features.

RESULTS

Primary stems achieved less than 10-year survival rates than revision stems (85.9% vs. 92.3%; P < 0.0001). Primary stems achieved lower 10-year survival rates with specific end points, aseptic loosening (P = 0.0005), and periprosthetic fracture (P < 0.0001) but not primary instability (P = 0.011). The survival rates of the four cohorts stratified for modularity demonstrated different 10-year survival rates (single-taper primary stems: 84.1%; modular primary stems: 87.9%; single-taper revision stems: 94.5%; modular revision stems: 91.2%; P < 0.0001). In revision surgeries due to aseptic loosening, primary stems achieved lower survival rates, especially in women aged more than 65 years (P = 0.021). Single-taper primary stems achieved lower performances than single-taper revision stems (P < 0.001).

DISCUSSION

Primary stems should be carefully adopted in femoral component revision surgeries, especially in women aged 65 years or older. Single-taper primary stems carried a notable rate of failures at 10 years in comparison to single-taper revision stems.

LEVEL OF EVIDENCE

III, therapeutic study.

Management of Severe Bone Defects in Femoral Revision following Total Hip Arthroplasty

Treatment of femoral bone defects continues to be a challenge in revision total hip arthroplasty (THA); therefore, meticulous preoperative evaluation of patients and surgical planning are required. This review provides a concise synopsis of the etiology, classification, treatment strategy, and prosthesis selection in relation to femoral bone loss in revision THA. A search of literature was conducted for identification of research articles related to classification of bone loss, management of femoral revision, and comparison of different types of stems. Findings of a thorough review of the included articles were as follows: (1) the Paprosky classification system is used most often when defining femoral bone loss, (2) a primary-length fully coated monoblock femoral component is recommended for treatment of types I or II bone defects, (3) use of an extensively porouscoated stem and a modular fluted tapered stem is recommended for management of types III or IV bone defects, and (4) use of an impaction grafting technique is another option for improvement of bone stock, and allograft prosthesis composite and proximal femoral replacement can be applied by experienced surgeons, in selected cases, as a final salvage solution. Stems with a tapered design are gradually replacing components with a cylindrical design as the first choice for femoral revision; however, further confirmation regarding the advantages and disadvantages of modular and nonmodular stems will be required through conduct of higher-level comparative studies.

Cementless Primary Stems in Revision Hip Arthroplasty: A Narrative Review

Cementless primary stems in revision hip arthroplasties may be conservative options to preserve bone stock and provide adequate reconstruction of the hip biomechanics. However, there is still little evidence about indications, limitations, and outcomes. This narrative review showed that conventional standard stems were adopted in different revision settings, up to Paprosky IIIA grade bone defects. In cases of acceptable metaphyseal bone stock, when a scratch fit of at least 4 cm can be achieved, a conventional cementless stem may be an adequate solution. Mid-term clinical and radiographic outcomes and survival rates were similar to long revision stems, whereas complications, surgical time, and costs were lower among conventional stems. However, unsuitable contexts for conventional stems included canal diameters larger than 18 mm and failed revision stems with cortical weakening. Even short stems can be considered in revisions, in order to preserve bone stock and stay proximal to femoral remodeling zones and bone/cement plugs. Short stems were successfully adopted up to Paprosky IIIA bone defects, achieving mid-term survival rates not inferior to long revision stems. Ageing, osteoporosis, and intraoperative femoral fractures were the main negative prognostic factors. In very select cases, a downsizing technique (from longer to shorter stems) may be adopted to simplify the procedure and reduce complications.