Comparison of radiographic changes in rectangular curved short stem with thin versus thick porous coating for cementless total hip arthroplasty: a retrospective study with a propensity score matching

Abstract

Background Radiographic changes that appear relatively quickly after fixation of cementless stem in total hip arthroplasty (THA) vary depending on the stem design and fixation style. The present study compared radiographic changes between two types of rectangular curved short stems of similar shape. Methods This retrospective study included 118 hips that underwent primary cementless THA with an anterolateral supine approach using a rectangular, curved, short stem performed by the same surgeon between June 2015 and June 2019. Among the examined hips, 39 had a thicker porous coating stem (thicker group) and 66 had a thinner porous coating and reduced tip stem (thinner group) and at least 12-month follow-up. Radiographs taken during the final course observation were assessed. Propensity score matching was performed based on demographic data and comparisons were made using pairs of 25 hips each. Statistical analysis was performed using chi-square test and p values ≤ 0.05 indicated statistical significance. Results The pattern of the radiolucent lines showed a significant difference after matching (p = 0.0044). A “proximal and distal” pattern was most common in the thicker group and a “distal only” pattern was most common in the thinner group. There was notable and significant difference in cortical hypertrophy in the thicker group after matching (p = 0.024). Conclusions Although the two short stems were similar shapes, the short-term radiographic changes were different. The thinner group showed fewer radiographic changes than the thicker group, making it a more “silent” stem.

Effect of femoral stem surface coating on clinical and radiographic outcomes of cementless primary total hip arthroplasty: a patient-matched retrospective study

“…Level of evidence: level III, retrospective cohort study studies have investigated the effect of other stem coatings on the clinical and radiographic outcomes of THA [11][12][13].…”

A Radiographic Evaluation of Short Monolithic Femoral Hip Stem (SMF) for Dysplastic Osteoarthritis: Does Stem Alignment Influence on the Stability?

“…Dysplastic patients are relatively young and have high activity [1] [2]. For such young and active patients, femoral bone preservation is an essential issue, considering the revision in the future [3] [4]. Recently many types of uncemented short stems have been designed to preserve the bone stock and at the same time to ease the insertion procedure in MIS-THA [4] [5].…”

“…For such young and active patients, femoral bone preservation is an essential issue, considering the revision in the future [3] [4]. Recently many types of uncemented short stems have been designed to preserve the bone stock and at the same time to ease the insertion procedure in MIS-THA [4] [5]. Each type has different concept to obtain the initial and long-term stability in the femur [4] [5].…”

“…Recently many types of uncemented short stems have been designed to preserve the bone stock and at the same time to ease the insertion procedure in MIS-THA [4] [5]. Each type has different concept to obtain the initial and long-term stability in the femur [4] [5]. Short Monolithic Femoral hip stem (SMF TM ) (Smith & Nephew, Inc., Memphis, TN, USA) (Figure 1) is a short stem and was improved as a modification of SYNERGY Stem (Smith & Nephew, Inc.) [6].…”

“…Because of recent spread of MIS procedure, the usage of short stems has been increasing in THA [4]. Short stems seem to allow preservation of bone stock, with decreased stress shielding and also a lower incidence of thigh pain, compared with conventional stems [21].…”