Endofemoral Shooting Technique for Removing Well-fixed Cementless Stems

Cementless fixation in total hip arthroplasty (THA) has been increasingly used worldwide. Furthermore, the number of revision THAs has inevitably increased.

The removal of a well-fixed cementless stem poses technical challenges.

Kenichi Oe et al had been performing an endofemoral shooting technique for the removal of well-fixed cementless stems since 2001. They conducted a retrospective study to evaluate the clinical results of this technique. The study has been published in "Arthroplasty Today" journal.

118 consecutive revisions following bipolar or total hip arthroplasty, which required cementless femoral stem removal, were performed at the authors' institution (Kansai Medical University, 2-5-1 Shinmachi, Hirakata, Osaka Japan). The study evaluated 106 patients (108 hips) who were followed up for a mean of 9.2 years (range, 5-20 years). The patients included 15 men and 91 women with a mean age of 65 years (range, 33- 87 years). Endofemoral extracted stem removal was performed as follows.

Multiple Kirschner wires were sequentially inserted into the interface between the implant and cortical bone, after which the implant was detached using a thin chisel. After the cementless stem was removed, it was replaced with a cemented stem using an autograft, as needed. Radiological loosening of the femoral stem was defined as definite or probable loosening, based on the criteria of Harris et al. Prosthesis survival was analyzed using the Kaplan-Meier method, with the endpoint set as repeat revision surgery for stem loosening or femoral fracture.

Key findings of the study:

•The mean Merle d'Aubigne Clinical Score signi ficantly improved from 10.4 points (range, 2-15 points) preoperatively to 15.4 points (range, 9-18 points) at the last follow-up (P < .05).

•Re-revision surgery was performed in 7 hips.

•The mean subsidence was 0.3 mm (0-3 mm) at the final follow-up or immediately before revision surgery.

•Stem loosening was observed in 4 hips, and the mean subsidence was 0.3 mm (0-3 mm).

•The 10-year survival rate was 97.7% (95% confidence interval, 93.2-100).

The authors concluded that - "Our technique is safe and reliable for removing well-fixed cementless stems in patients who underwent BHA or THA. It can avoid an ETO or split procedure although it has technical requirements. Thus, this technique can be used as an alternative to ETO for removing well-fixed cementless stems although care should be taken when handling a category D cementless stem design."

Further reading:

Endofemoral Shooting Technique for Removing Well-fixed Cementless Stems Kenichi Oe, Hirokazu Iida et al Arthroplasty Today 17 (2022) 36-42 https://doi.org/10.1016/j.artd.2022.07.007