The current review showed an increasing trend in publications discussing and reporting on SHD over the past 20 years from authors worldwide concerned with treating traumatic and non-traumatic conditions. Also, its use in adult patients is well established, and applying this approach to paediatric patients is becoming more popular and has increased tremendously over time.

Providing 360 degrees view of the acetabulum and the femoral head while preserving hip joint vascular supply made SHD approach a revolution in hip surgery. Furthermore, the efficacy and safety of utilizing this approach in managing traumatic and non-traumatic hip joint conditions were well documented in the literature [11,12,13,14,15,16,17].

Although Ganz et al. reported that they have been using SHD since 1992 [6]; however, after carrying out a PubMed search using the same search terms we used in the current review to check if there were any publications on SHD in the 10 years before 2001, the search revealed no results. This indicates that SHD was not generally accepted by the orthopaedic community until the initial results concerning its safety were published in 2001 [6], which encouraged wider adoption by more surgeons.

Furthermore, as the initial description was titled “Surgical dislocation of the Adult hip,” [6], we noticed that it was not until 2007 that the first article discussing the utilization of SHD in paediatric patients was published [18], followed by an increasing trend over the following years. Furthermore, intra-articular osteotomies to treat paediatric hip conditions were revolutionized after the addition of the extended retinacular flap to the SHD [19]. In a questionnaire study performed on members of the Paediatric Orthopaedic Society of North America by Thawrani et al. investigating their patterns of treating SCFE, the authors found that surgeons with less than 15 years of experience, those who work in academic practice, and surgeons treating a greater number of SCFEs are utilizing SHD more often to reduce the slip acutely [20].

Worth mentioning that the application of SHD in paediatric patients varied among studies, where some applied the same surgical technique as reported in adults [21, 22]; however, Smith et al. raised a concern regarding the possible injury of the proximal femoral physis and greater trochanter apophysis while performing TFO to achieve surgical hip dislocation, so the authors advocated performing SHD without TFO in patients younger than eight years old by elevating a small cartilaginous sleeve from the greater trochanter apophysis with the vastus lateralis, and abductor muscles still attached [23].

Several factors enabled SHD to be more popular among orthopaedic surgeons over time:

First, the lower incidence of AVN compared to other approaches when treating traumatic or non-traumatic hip conditions [6, 12], was owed to the preservation of hip external rotators, which subsequently protect the MFCA and performing a Z-shaped capsulotomy which allows raising a retinacular flaps, which contributes to blood supply preservation [6, 7, 24]. Furthermore, the vascularity status could be evaluated intraoperatively through a small perforation in the head, and a bleeding sign was correlated positively with the femoral head viability [6, 25]. Some authors described using intraoperative laser Doppler flowmetry as proposed by Nötzli et al. [26].

Second, the generous 360 degrees visualization of both the acetabulum and the femoral head, with further unobscured visualization of the hip central compartment, enables full assessment and treatment of labral and chondral injuries, as well as excision of various lesions and fixation of fractures [13, 25]. Moreover, as FAI was the most commonly treated condition through SHD, this approach enables easy visualization of osteochondroplasty. It was also efficient in addressing atypical and posterior rim and cam FAI, which are difficult to be treated arthroscopically [27].

Third, when dealing with sequelae of paediatric hip conditions such as Perthes disease and SCFE, which are often associated with relative femoral neck shortening, which could lead to the development of ischia-femoral or trochanteric pelvic FAI, distalization of the TFO could achieve relative neck lengthening with further improving the mechanical properties of the hip abductor complex [28].

Fourth, Ganz et al. reported treating various conditions, which were mainly non-traumatic conditions related to FAI (84%), sequelae of Perthes’ disease (11.3%), and pigmented villonodular synovitis, synovial chondromatosis or cartilaginous exostosis (4.7%) [6]; however, the current review proved that SHD showed great versatility for managing various traumatic and non-traumatic conditions over time which are difficult to treat arthroscopically or through other hip approaches [27].

Although SHD is an appealing approach with a wide margin of safety, however, it carries some complications;

First is the relatively high incidence of heterotopic ossification (HO) formation; Ganz et al. reported an HO incidence of 37%, and two patients diagnosed with HO grade III required surgical excision [6]. Kargin et al. evaluated 44 patients who underwent SHD for non-traumatic conditions; they reported an incidence of HO formation of 36.5% and lateral thigh pain of 28,8% [29].

Second, the unique complications associated with SHD are the TFO non-union and chronic lateral thigh pain from prominent screws fixing the TFO, with the possibility of further surgery either to fix a non-united TFO or to remove prominent lateral screws. Ganz et al. reported three (1.4%) cases with TFO non-union [6]. In a multicentre study by Sink et al., they evaluated 334 hips that underwent SHD with a minimum 12-month follow-up, although they reported no AVN; however, TFO non-union was reported in six hips (1.8%), all united after revision of the internal fixation [30]. Some authors reported an incidence of residual lateral thigh pain in up to 46% of the patients, which did not influence the clinical outcomes [29, 31].

To overcome the previously mentioned complications, some authors reported performing SHD without needing TFO. Shannon et al. [32] described performing SHD through a modified Hardinge approach in an adult patient for excising an osseocartilaginous lesion of the acetabulum and the femoral neck; without performing a TFO; instead, they exposed the hip capsule by elevation off 20% of the gluteus medius of the greater trochanter which was retracted anteriorly with the rectus femoris, and the hip was dislocated anteriorly by gentle hip external rotation. At one year follow-up, they reported good outcomes. The same previous approach (modified lateral) without TFO was used in a study by Schweitzer et al. [33], including six hips (five adults and one paediatric), and no complications or AVN were detected after a minimum of two years of follow-up. Furthermore, an anterolateral (Watson jones) approach to the hip without the need for TFO was described in a report by Louahem et al. [34] to treat 15- and 16-year-old patients presented with hip OCD.

Third, the issue of the learning curve and the need for special training before adopting SHD were not discussed thoroughly in the literature; however, in some reports, the authors mentioned their inability to utilize SHD owing to unfamiliarity [35]. Furthermore, Smith et al. stressed the point that SHD should not be done in paediatrics unless the surgeon is familiar with the SHD technique, hip joint anatomical variation, and has a good understanding of different pathologies [23].

The current review has some limitations; first, we only included one database in our search, which could deprive other publications not indexed in PubMed from being included. Second, additional bibliometric parameters, such as the number of citations for each article, were not included in the analysis. Third, we did not evaluate the quality of the included studies, such as their evidence level and the possible bias.