Total hip arthroplasty (THA) is one of the most commonly performed procedures and its incidence is increasing exponentially in the last decades along with the increase in life expectancy ^[1,2]. It is considered the gold-standard treatment of end-stage of hip osteoarthritis as it offers relief from pain, improved mobilization and quality of life ^[1,2]. More importantly, the excellent long-term outcomes reported in the literature, have rendered THA to be described as the operation of the century ^[3]. However, along with the increase in primary THA incidence, there is a consequent increase in THA revision rates.^[1,4] In fact, an increase of up to 70% is expected until 2030 ^[1]. Revision surgeries are challenging to treat and cause significant financial burden to patients and healthcare systems ^[1,5,6]. Taking into account that in the last years a growing number of young patients is subjected to THA and the implants have a limited survival period, it is reasonable for the surgeon to consider that these patients will need in the future one or more revision surgeries ^[7]. Thus, it is clear that the preservation of as much bone stock as possible is of utmost importance, especially for this group of patients. Cementless short femoral stems have gained in popularity in the last decades. In the current literature, there is neither a clear definition for these stems nor a standardized classification system [8-14]. The following two definitions seem to be the most prevalent: Short stems are considered those whose total length is less than twice the vertical distance between the tip of the greater trochanter and the base of the lesser trochanter or those stems whose total length is <120 mm ^[8,15,16]. Despite the existence of several classification systems, none of them provides a fully integrated approach, and none is widely adopted in clinical practice ^[10,17]. Routinely, revision surgeries are accompanied by extended skin incisions, bone osteotomies, and excessive bone loss. For these reasons, more complex implants and longer stems are used, so sufficient anchoring in the diaphysis could be achieved ^[4,7,15]. The use of a short stem as a revision implant is still considered an “off-label’’ indication. Although it may seem reasonable when short stems are used for the revision of a failed hip resurfacing arthroplasty or in failed internal fixation of a proximal femoral fracture, their use when revising a conventional THA is considered unconventional ^[18,19]. Therefore, the evidence in the literature regarding this application is still scarce ^[4,15]. The objective of this study is to present a case report of a revision THA using a short stem implant, with the aim of providing valuable insights in respect to indications, technique, and advantages of this approach. This study aims to contribute to the literature by providing significant information and stimulating further research on a yet under-reported topic.

A 64-year-old male patient presented to the orthopedic outpatient department complaining of painful right THA during his everyday activities and severe limping. The indication for the primary THA was end-stage primary hip osteoarthritis and it was performed 7 years ago through the modified Hardinge’s approach. The past medical history included benign prostatic hyperplasia. The clinical evaluation revealed approximately 2.5 cm leg-length discrepancy and at the standard pre-operative radiological evaluation it was identified loosening of the right femoral stem since radiolucent lines around the stem, anterior thigh pain, and varus malalignment were evident. The pre-operative work-up was negative for infection, and aseptic loosening was considered the final diagnosis. The severe leg-length discrepancy and the high hip center were the two main reasons for the revision of the acetabular component. A modified Hardinge’s approach was performed. After the removal of the acetabular and femoral components, a thorough debridement of the acetabular bone bed and the femoral canal was performed until sufficient bleeding was evident. The femoral bone defect was classified as type I whereas the acetabular bone defect was classified as type IIIA according to Paprosky classification (type III according to Saleh classification) ^[20,21] (Fig. 1). Moreover, intra-operative tissue samples were collected and sent for microbiological cultures which were finally negative. The acetabular bone defect was addressed with a cup-cage construct in conjunction with the impaction of morselized allograft (fresh-frozen femoral head). The ischial hook was placed at the obturator foramen and the iliac flanges were adjusted accordingly to the iliac bone and stabilized with five screws. The femoral component was revised using a type 3 (trochanteric sparing) short stem since there was sufficient bone stock and of good quality the proximal femur. Before the placement of the final components, an intra-operative fluoroscopic image was obtained to confirm the correct sizes and position of the implants.

The post-operative course was uneventful and at the final 27 months of follow-up, the patient was free of pain and reported excellent patient-reported outcome measures (PROMs) (Harris Hip Score=93.85, Oxford Hip Score=41, Forgotten Joint Score=86.36, Patient Health Questionnaire-9=0, EQ-5D-5L=0.928, Pain Catastrophizing Scale=2, visual analogue scale=1). No radiolucent lines were observed around the stem as well as around the acetabular component. Moreover, the allograft osseointegration was classified as successful according to the Oswestry radiological classification system ^[22]. Small amounts of heterotopic ossification were developed in the right hip joint both at the lateral (Brooker 1) and medial side (type 3) ^[23,24] (Fig. 2).

The increase in primary THA incidence has led to a subsequent increase in THA revision rates ^[1,4]. In the current literature, it still remains unclear whether the more active lifestyle of the patients, especially the younger ones, leads to a more accelerated loosening of the implants ^[25]. Considering the increasing trend of younger patients undergoing THA in the last decades, coupled with the finite lifespan of implants, it is prudent for surgeons to anticipate the likelihood of these patients requiring one or more revision surgeries in the future ^[7]. Consequently, it becomes evident that preserving the maximum possible bone stock is crucial, particularly for this demographic. Short stems are accompanied by numerous advantages as their design aims to mimic the proximal femoral anatomy and hip biomechanics ^[26]. They are less invasive, in the context of causing less damage in the proximal femur, since less bone is removed during femoral canal’s broaching. Moreover, they allow for easier insertion and more physiological loading which subsequently leads to less stress shielding compared to standard stems. Furthermore, they can be used in femurs with special-unique proximal anatomy such as in cases with proximal-distal mismatch, and they have been associated with diminished anterior thigh pain ^{[2,8,11,16,27,28]}. All these features have rendered short stems attractive to the contemporary orthopaedic hip surgery and have led many hip surgeons to include them into their armamentarium ^[28]. Despite the unique characteristics and the potential benefits of the short stems, there is still a lack of clarity regarding their indications and contraindications. Subsequently, their implementation is depended on surgeon’s preference and experience ^[7]. However, there are some key points that a hip surgeon should bear in mind when this implant type is utilized. First and foremost, good bone quality of the proximal femur is necessary in order to achieve a stable press-fit fixation ^[7,29]. However, this does not mean that preoperatively the patients need to undergo bone mineral density testing. Moreover, advanced age, high body mass index, Dorr C femoral canal, rheumatoid arthritis, post-traumatic arthritis, and proximal femoral deformities (with or without previous corrective osteotomies) are not absolute contraindications for the implementation of a short femoral prosthesis ^[7,27,30]. The concept of downsizing the femoral component in a revision setting was initially introduced in a limited case series of Coutandin et al. The study reported excellent results, both clinical and radiological, without serious complications in the mid-term follow-up (100% survival rate, mean follow-up=3.32 years), concluding that this approach may offer advantages in selected cases ^[4]. However, the principles of revision arthroplasty should always be adhered to ensure optimal patient outcomes. Some key principles include: stable implant fixation, preservation of as much bone stock as possible (in the already compromised), and minimization of surgical trauma along with its consequences ^[31]. Considering all the aforementioned principles and the extensive experience of our major joint reconstruction unit in utilizing short stems during primary total hip arthroplasties, we were able to employ the “downsizing” approach for the femoral component using a type 3 short stem (trochanteric sparing type) ^[8,32]. The short femoral prosthesis was implanted easily, achieved excellent short-term outcomes, both clinically and radiologically, maintained the bone mineral density as its conventional counterparts and did not cause anterior thigh pain ^[12,26]. Our patient did not experience any minor or major post-operative complications, was free of pain and reported excellent PROMs in the short-term follow-up period.

Short stems are gaining in popularity in the contemporary orthopedic surgery with various implants being available regarding their design and features. However, their use is mainly restricted to primary THAs in young patients with good bone quality in the proximal femur. There are only scarce reports (including the current one) of short stems being used as “off label” revision implants, showing good-to-excellent outcomes. Despite the promising reported outcomes, further studies are needed to confirm their efficacy either as a primary or as a revision implant in cases with the corresponding indications. Nevertheless, in order to give clear answers to all these questions, it may be necessary to clarify firstly their definition and adopt a single-unified classification system.

Short femoral stems offer a viable option for revision THA, particularly in younger patients with preserved bone quality. Despite being considered an “off-label” approach, short stems provide several benefits, including reduced bone resection, less stress shielding, and the potential for improved patient outcomes with fewer complications. While these advantages make short stems an attractive choice in revision settings, further research is necessary to solidify their role, particularly in defining their indications, contraindications, and a standardized classification system. This study contributes valuable insight into the use of short stems in revision THA, supporting the need for additional exploration in this area.