1. Introduction

2. Surgery Benefit Pipkin Type I Femoral Head Fractures 

With regards to mechanism of injury, femoral head fractures typically occur following motor vehicle injury and associated dashboard injuries. 89.7% of patients sustained a femoral head fracture following a MVA while 5.2% and 1.0% of patients fell from either a height or direct impact from falling debris, respectively. Early detection and closed reduction are critical in the initial patient management, especially among poly-trauma patients as femoral head fracture can be undetected.

Type I Pipkin femoral head fractures are inferior to the fovea capitis femoris, the non-weight bearing surface of the femoral head. Appropriate treatment options for Pipkin Type I femoral head fractures must consider joint reduction, hip stability, and congruent joint line. The presence of intra-articular incarcerated fragments impedes a congruent joint reduction [24,25,37]. Chakraborti et al. recommended that conservative management should always be considered first [38]. Historically, femoral head fractures were treated conservatively with prolonged bed rest, in-line traction, and closed reduction. Non-operative management in Pipkin Type I femoral head fractures can be considered if closed reduction achieves <1–2mm displacement and an anatomic congruent hip joint without evidence of fragment interposition. Henle et al. reported that only 1 of 12 patients was in anatomic position following closed reduction [2]. In our analysis, conservative treatment with closed reduction alone for the dislocated hip joint increased the rate of posttraumatic arthritis as well as leading to poor Merle’ d Augine and Postel outcome scores. Supporting our findings, Chen et al. conducted a randomized control trial to assess functional outcomes of 16 Type I Pipkin fractures who either receive closed reduction or closed reduction with fragment excision [26]. Thompson and Epstein and Merle d’Aubigne and Postel scores were both worse for conservative treatment with closed reduction alone (p  =  0.032).

Holmes et al. conducted a biomechanical cadaveric study indicating that excision of a small part (<1/3) of the non-weight-bearing surface does not lead to adverse long-term clinical implications [39]. Contrastingly, the literature has reported that retained intracapsular fragments contribute to synovial joint degeneration, chondrocyte apoptosis, and soft tissue destruction [40].

Fragment size is also critical to predict the prognosis such as the rates of posttraumatic arthritis, AVN, and HO. To further guide appropriate treatment of different fragment size in Pipkin Type I, Yoon et al. modified this classification to: (a) small fragment or several fragments require fragment excision; (b) large fragment requires fragment anatomical reduction [34]. Unfortunately, most studies did not show a consistent inclusion criteria of fragment size. Therefore, the role of different fragment size which impact on treatment decision was difficult to draw conclusions from the literature [34].

Fragment excision as well as open reduction internal fixation are viable surgical options for isolated femoral head fracture, yet results remain inconclusive. Pape et al. reported that 75% of patients reported satisfactory outcomes following closed anatomic reduction alone of Pipkin Type I femoral head fractures as compared to 64% and 50% who either underwent ORIF or fragment excision, respectively. Contrastingly, Giannoudis et al. reported that among 71 Pipkin Type I femoral head fractures, patients who underwent fractured fragment excision reported an 86.7% “excellent” or “good” Thomson-Epstein functional outcome scores, yet not significant when compared to ORIF patients (p = 0.07). Furthermore, Epstein et al. reported that among 242 posterior-femoral head fracture dislocations, satisfactory results were achieved in 12%, 42%, and 63% of patients that either received closed reduction alone, closed reduction followed by open reduction, and primary open reduction, respectively [39].

The results indicate that fragment excision had better functional outcomes in both Thompson Epstein and Merle’ d Augine and Postel Scores when compared to conservative treatment alone or ORIF. We suggest a conservative treatment with closed reduction as the first step for these types of injuries. If a noncongruent hip joint remains, excision or ORIF should be considered accordingly to the fragment size. A small fragment may be excised while a large fragment may be treated with ORIF by screw fixation.