Abstract
Introduction
The concept of neck preserving stems, known as short femoral stems or metaphyseal stems has been utilized to improve the outcomes of standard cementless stems. The preservation of the proximal femoral bone stock results in decreasing the potential stress shielding and thigh pain. Additionally, these stems may be used in less invasive procedures and provide the option for easier revision procedures if implant failure occurs. In this study we aim to demonstrate the clinical outcome of direct anterior approach of total hip arthroplasty (THA) with short stem prosthesis.
Methods
In this study, 390 total cases of THA in 345 patients who underwent an anterior approach of THA by using a new type of short-stem prosthesis (Minihip, Corin) between 2009 and 2013 were reviewed.
There were 282 male and 62 female patients and Table 1 summarizes the demographics. In 48 cases avascular necrosis (AVN) was the diagnosis and 339 cases were reported to be due to osteoarthritis. Twenty eight patients were assessed to have American Society of Anesthesiologist (ASA) physical functional score of class I, 258 patients had class II, 103 had class III, and 1 had class IV. Table 2 shows the Charnley classification of the patients.
In the current study we evaluated the outcomes of the surgery by utilizing Hip Disability and Osteoarthritis Outcome Score (HOOS) subscales (Pain, Symptoms, Function in daily living (ADL), Function in sport and recreation (Sport) and hip related Quality of life (QOL)).
Results
All HOOS subscores were significantly increased from preoperative assessments (F (5,97) = 1679, p < 0.001). The outcome are summarized in Table 4 and Figure 1. No failure of the implant has yet been reported however in 9 cases (2%) calcar fracture occurred during the surgery that were successfully treated with cerclage wires. While no implant loosening was observed, there were four cases (1%) with asymptomatic subsidence (≥ 2mm).
Conclusion and Discussion
This study continues to support the excellent clinical outcomes of this short-stem prosthesis when is used for primary total hip arthroplasty. Based on the current findings, we expect that this short stem implant is an excellent choice particularly for younger individuals.
