An active twenty-eight-year-old male wrestling instructor presented with right hip pain. Five months previously, he had sustained a twenty-foot fall that resulted in a posterior dislocation of the hip. He had undergone closed reduction, and postreduction radiographs and a computed tomography (CT) scan had demonstrated an isolated femoral head fracture located anterosuperiorly relative to the fovea (Pipkin II). The physicians had opted to treat the fracture nonsurgically. The patient had been kept non-weight-bearing for three months, and he had then been allowed to progressively bear weight as tolerated; he had returned to full activities when the radiographs had shown a healed fracture. The patient, however, had continued to note groin pain with hip flexion. He also had described mechanical symptoms of “popping” and “catching.”
On presentation to our office, the symptoms were moderate, persistent, activity-related groin pain in addition to limitations with hip flexion. The modified Harris hip score was 65. He had an antalgic gait, and hip motion was limited, with passive flexion from 0° to 60°. A mechanical block was noted: the pelvis would flex with additional attempted hip flexion. Internal and external rotation were 0° and 10°, respectively, at 60° of flexion. Abduction and adduction were limited to 20° and 10°, respectively. Provocative maneuvers, including an anterior impingement test and Patrick’s flexion, abduction, and external rotation test, were positive for groin pain. Radiographs demonstrated a femoral head fracture malunion located at the anterosuperior aspect of the femoral head (Figs. 1-A, 1-B, and 1-C), which was better defined with CT (Figs. 2-A and 2-B). A magnetic resonance (MR) arthrogram noted a labral tear and a femoral head chondral defect (Figs. 2-C and 2-D). Because of persistent pain, restricted hip motion, an incongruous joint surface, and secondary FAI, surgical dislocation of the hip was recommended for femoral head malunion correction and treatment of the associated labral and chondral disease.
The patient underwent surgical dislocation of the hip, as previously described by Ganz et al.6. An oblique trochanteric osteotomy with anterior dislocation of the hip and preservation of the medial femoral circumflex artery was performed to provide unrestricted access to the proximal part of the femur and acetabulum. A malunion at the anterolateral femoral head/neck region was present, measuring approximately 15 × 25 mm, with 7 to 8 mm of anteroinferior displacement (Figs. 3-A and 3-B). Dynamic testing with hip flexion and internal rotation confirmed an “inclusion-type” FAI, where the proximal femoral prominence (malunion deformity) was “included” into the acetabulum during hip flexion, resulting in a “jamming” effect at the labral-chondral junction. Inspection of the central compartment revealed a 15-mm superolateral acetabular labral tear with an associated partial-thickness acetabular chondral flap (not extending to bone) that measured 15 mm × 5 mm. These lesions were located in the area of abutment of the malunited fracture during dynamic testing. The labrum was repaired with three corkscrew suture anchors after the acetabular rim was prepared with a round-tip burr. The adjacent partial-thickness chondral flap was debrided to stable underlying articular cartilage.
The malunited fragment was freed from the femoral head by inserting thin osteotomes at the edges of the fragment, following the old fracture line until it was free of the underlying femoral head. The osteotomy was tapered at an angle toward the center of the malunion, creating a fragment that was approximately 1 cm thick at the midline. Once the fragment was mobile, it was peeled back, and the underlying femoral head cancellous bed was prepared with the use of a round burr to remove prominent bone and fibrocartilage that had grown into the region of displacement. The fragment was then anatomically reduced, as confirmed with a spherometer (Figs. 4-A through 4-D). This fragment was then fixed in place with two 30-mm-long Acutrak Mini screws (3.6-mm diameter; Acumed, Hillsboro, Oregon). There was notable bleeding from the screw sites, thus confirming good blood supply from the underlying cancellous bed of the intact femoral head. Radiographs confirmed a concentric reduction, and a round burr was used to correct a cam-type deformity and insufficient offset at the anterolateral femoral head/neck region to relieve the FAI and protect the labral repair.
Postoperatively, the patient was managed with a continuous passive motion device, isometric exercises, and progressive weight-bearing and strengthening. Specifically, he was toe-touch weight-bearing for eight weeks, and he then progressed to full weight-bearing. The patient was released to full activities three months after surgery. At the seventeen-month follow-up, he had mild pain and no activity limitations. The modified Harris hip score had improved to 85 points. He demonstrated full symmetric range of motion and a negative impingement test as well as no radiographic changes of osteonecrosis, loss of reduction, or joint-space narrowing. The femoral head fracture had healed (Figs. 5-A, 5-B, and 5-C). He had returned to unrestricted activities, including jogging and wrestling.
Although rare, femoral head fractures are increasing in frequency, likely a result of an increase in motor vehicle accidents and improved patient resuscitation/survival7. Given the tendency for displacement and joint incongruity, most femoral head fractures are treated surgically. Past reports demonstrate similar outcomes between patients treated with femoral head fracture fixation and those treated with excision8,9. A cadaveric investigation performed by Holmes et al.10 demonstrated no change in load and/or mean and peak pressures of the femoral head when comparing intact femoral heads and femoral heads with an excised Pipkin-I fragment. When larger fragments, such as those seen in Pipkin-II fractures, were excised, this resulted in altered peripheral loading patterns and higher contact pressures located centrally within the acetabulum. This mechanism is thought to be responsible for the rapid deterioration of the chondral surfaces after larger fragment excisions. Given the considerable size of the fragment as well as its location in the weight-bearing portion of the femoral head in our patient, we opted to salvage the fragment rather than perform an excision.
To our knowledge, this is the first report of an intra-articular femoral head malunion corrective osteotomy. Previous cases of corrective intra-articular osteotomies in other joints have been reported with good results11-16. We believe that only one previous case series is documented with regard to malunited femoral head fractures17. Three patients with malunited Pipkin-I femoral head fractures underwent ostectomy because of limited hip motion. Excellent results were obtained in all three patients, with near complete restoration of hip motion. Our patient essentially had a large osteochondral fragment that was freed, reduced, and internally fixed. A previous case report by Nam et al.18 described a patient with a similar fracture pattern that was treated eleven days after injury with reduction and fixation, as well as with the addition of an osteochondral autograft plug from the inferior, non-weight-bearing portion of the femoral head. An MRI performed at one year postoperatively demonstrated healing of the fracture and a well-incorporated autograft plug. This patient reported no pain and was back to baseline activities five years postoperatively.
Previous cases of femoral head allograft treatment for osteochondral defects have also been reported. Initially, this technique was used for the treatment of osteonecrosis, with the best results noted in patients with osteonecrosis that was not corticosteroid related19,20. Femoral head osteochondral allografts have also been used for posttraumatic defects21 and osteochondritis dissecans22 of the femoral head, with complete graft incorporation and excellent clinical outcomes. In our case, given the good health of the articular cartilage and the inherent difficulty of obtaining a fresh, size-matched allograft, we opted to use the native femoral head fragment. The femoral head healed uneventfully, vascularity was maintained, and the procedure was associated with a good short-term clinical result. Application of this technique is limited; it can be successful when the patient has optimal conditions with good bone quality and a large osteochondral fragment with relatively intact articular cartilage, as in our case. There is, however, still a risk of fragment osteonecrosis and/or the subsequent development of osteoarthritis; therefore, we will continue to follow our patient.
Open surgical dislocation of the hip has been successfully utilized in patients treated for acute acetabular fractures, fractures of the femoral head, and various FAI deformities. This approach allows optimal exposure for complex FAI disorders; this case report indicates that the technique can be used to treat femoral head fracture malunions.
Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. One or more of the authors, or his or her institution, has had a financial relationship, in the thirty-six months prior to submission of this work, with an entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. No author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.