The clamshell fracture and adjunctive acetabuloplasty in the arthroscopic osteosynthesis of femoral head fractures with femoroacetabular impingement

Arthroscopic Reduction and Fixation of a Pipkin Type-I Femoral Head Fracture

Background

This video article describes the technique for arthroscopic reduction and fixation of Pipkin type-I fractures.

Description

Surgery is performed with the patient in a supine position, with free lower limbs, on a radiolucent table. Arthroscopic superior and anterolateral portals are made similarly to the portals created to evaluate the peripheral compartment during an outside-in (ballooning) technique.1 An additional medial portal is subsequently created in order to aid in reduction and screw placement. The medial portal is created in abduction and external rotation of the hip (i.e., the figure-4 position). The adductor tendon is identified, and the portal is then safely positioned posteriorly to its margin, approximately 4 to 5 cm distal to the inguinal fold, avoiding the saphenous vein (usually identified with an ultrasound scan). The fragment is mobilized, debrided, and then reduced with use of a microfracture awl or a large Kirschner wire (used as a joystick). Following reduction, temporary fixation is performed with use of long Kirschner wires under direct visualization and fluoroscopic guidance. If reduction is satisfactory, definitive fixation can be performed with use of 4.5-mm headless screws through the medial portal. All steps of fragment reduction and fixation are performed through the medial portal, with the patient in the figure-4 position. Once the screws are placed, a final dynamic arthroscopic and fluoroscopic check is performed.

Alternatives

In Pipkin type-I fractures, surgery is recommended when the femoral head fragment is large (exceeding 15% to 20% of the femoral head volume) and displaced (by >3 mm). In such cases, if untreated, spontaneous evolution to osteoarthritis may occur. For fragments smaller than 10% to 15% of the femoral head volume, arthroscopic removal is often the best choice2. Several approaches (e.g., Smith-Petersen, modified Hueter, Kocher-Langenbeck, and surgical safe dislocation) have been proposed for reduction and fixation, with surgical safe dislocation being the most versatile because of the uniquely complete visualization of the femoral head3.

Rationale

The arthroscopic reduction and fixation technique for a non-comminuted Pipkin type-I fracture holds the intrinsic advantages of being less invasive than open surgery in terms of surgical exposure, and having less blood loss, infection risks, and wound complications. Arthroscopy allows direct visualization of the fragment and its reduction surface, along with removal of articular loose bodies and debridement. The surgical time is influenced by the surgeon's experience, but often is no longer than with an open procedure. In the few studies assessing the use of this technique, the rates of osteonecrosis and heterotopic ossification are lower than with open techniques. It is worth noting that the studies assessing the use of this procedure are limited both in number and quality; however, the results of these studies have been excellent. It must also be noted that patients undergoing arthroscopic fixation are mostly selected for this treatment because they have less severe injuries2-12.

Expected Outcomes

Open reduction and fixation through one of a variety of approaches is the gold standard treatment for Pipkin fractures; however, it is a relatively invasive procedure, prone to increased risks of osteonecrosis of the femoral head and heterotopic ossification (from 4% to 78% of cases). In some cases, arthroscopic reduction and fixation can be as effective as open reduction, and carries with it the intrinsic advantages of a keyhole procedure. The reported 4.6% global complication rate following arthroscopic fixation demonstrates the potential advantages of this technique, with limits due to the low numbers of treated cases4.

Important Tips

The operating room should be carefully set up, especially regarding the positions of the C-arm and the arthroscopy tower, which should be double-checked before starting the procedure.The medial portal should be created after identification of the saphenous vein on an ultrasound scan. The anesthesiologist or a radiologist may mark the vein on the skin preoperatively, or the surgeon may extend the arthroscopic portal and perform a superficial dissection to avoid the vessel.Visualization after creation of the portals is usually suboptimal until the hematoma is completely removed. Patience must be maintained in this phase of the procedure.A microfracture awl or a large Kirschner wire can be utilized as a joystick to aid in reduction of the fragment, from either the usual portals or the medial portal. This aid can facilitate rotation of the fragment, which is a key step in the reduction phase.Definitive fixation can be achieved with use of 4.5-mm cannulated headless screws. Large cannulated headless screws have longer and larger Kirschner wires that can also aid in reduction when used as joysticks, reducing the risk of bending or breaking during screw insertion. Additionally, a 4.5-mm screwdriver is longer, allowing easier insertion, especially in patients with a larger thigh. The large diameter should not be a concern because the head is sunk in a non-weight-bearing area of the head.To avoid the risk of misplacement or loss of the screw during its insertion, make use of a cannulated guide handle for 4.5-mm screws, such as the guide utilized in a Latarjet arthroscopic procedure.To prevent screw loss into the joint, utilize a loop-knotted wire around the proximal part of the screw; this wire is cut at the end of the procedure.

Acronyms and Abbreviations

AAFF = arthroscopic-assisted fracture fixationHO = heterotopic ossificationUS = ultrasound/ultrasonographyAP = anteroposteriorCT = computed tomographyASIS = anterosuperior iliac spineGT = greater trochanterSP = Smith-PetersenIF = internal fixationK-wire = Kirschner wire.

Arthroscopy-Assisted Reduction and Fixation of Femoral Head and Acetabulum Fractures: A Systematic Review of the Literature

Objective

To perform a systematic review to determine the current arthroscopic techniques of the fixation of femoral head and acetabulum fractures and assess the radiological and functional outcomes reported in literature written in English.

Methods

This review was performed by searching PubMed, Cochrane Library, Scopus, and Web of Science without a filter for time limitation in line with Preferred Reporting Items for Systematic Reviews Protocols (PRISMA‐P) guidelines. Two authors took part in screening and evaluating the literature between December 2020 and January 2021. The terms acetabulum fracture, reduction, fixation, femur head fracture, fracture dislocation of the hip, hip trauma and arthroscopy or arthroscopic, and their combinations were used to search four database engines in the titles and abstracts of the reported papers. Only papers with English titles and abstracts were included. The assessment of the data related to descriptions of the techniques, indications for fracture fixation using arthroscopy, and patient‐related outcomes.

Results

Perfect agreement was detected between the two reviewers during all steps of the review process (κ = 0.81–1.00). Although a meta‐analysis was planned to be carried out, no randomized controlled study comparing either the radiological or functional results of different surgical techniques was detected in the literature. Nineteen studies were included in the study. Of these, 15 were retrospective case reports and four were case series. Twenty‐seven patients were operated on for acetabulum fractures (18 male/nine female). The mean age was 28.3 years (range, 15–53 years). High‐energy traumas including motor vehicle accidents were the most common reason (81%). The duration of follow‐up was a mean of 32 months (range, 12–68 months). Sixteen patients were operated on for femur fractures (12 male/three female). The mean age was 30.1 years (range, 17–50 years). Motor vehicle accident was the most common trauma (70%). Duration of follow‐up had a mean of 18 months (range, 4–60 months). Patient‐related outcomes were excellent for reported cases in both groups despite the fact that an objective scoring system was not used for most of the cases. Moreover, there was no consensus on surgical indications or the techniques.

Conclusions

The techniques of arthroscopic‐assisted fixation of acetabulum and femoral head fracture are so heterogeneous that conclusions cannot be made at this time, but there is potential for this method of treatment to become more popular as the devices used in the procedure develop and as exposure to and experience with hip arthroscopy improves. Further descriptions of reduction and fixation techniques and analysis of outcomes of RCTs are needed.

Treatment of type IV Pipkin fracture in patients with a high BMI via hip arthroscopy-assisted surgery: a case report

Pipkin type IV femoral head (FH) fracture-dislocations are usually treated via open surgery. There are many surgical approaches for the treatment of this difficult fracture depending on the fracture pattern. Obesity presents another challenging problem in surgical treatment and sometimes leads to a poorer outcome. We discuss herein a patient of a high body mass index (BMI) with a Pipkin type IV FH fracture who underwent open reduction internal fixation (ORIF) of anacetabular fracture with reconstruction plates and hip arthroscopy-assisted fixation of the FH fracture with two Herbert screws via the posterior approach. The intra-articular osteochondral loose bodies were excised by hip arthroscopy simultaneously. The joint congruency and screw positions were checked during surgery by arthroscopy. After 6 months, clinical and computed tomography (CT) follow-ups showed excellent results. The patient of a high BMI recovered immediately and had a satisfactory short-term outcome after hip arthroscopy-assisted surgery. We concluded that hip arthroscopy-assisted surgery is a viable option for the treatment of Pipkin type IV FH fracture-dislocations.

Hip arthroscopy: a focus on the future

The indications for hip arthroscopy over the last decade have increased rapidly, driven by technical and technological advances aimed at hip joint preservation. This article reviews the current indications and supporting evidence for hip arthroscopy, explores some newer techniques/technologies and discusses the future directions in this rapidly evolving and expanding field.

The modified mid-anterior portal for hip arthroscopy

The modified mid-anterior portal is a utilitarian hip arthroscopy working portal that permits dual-portal comprehensive surgery for femoroacetabular impingement and related chondrolabral procedures without the need for interportal exchange. Its distal location facilitates labral reparative and reconstructive procedures while minimizing iatrogenic acetabular chondral damage. The relatively lateral location permits instrument navigation not only along the anterosuperior acetabular rim and anterolateral proximal femur typically required for acetabuloplasty and femoroplasty but even to the posterior regions of the hip in cases of global pincer femoroacetabular impingement and posterior extensions of cam morphology and the anteromedial proximal femur while avoiding direct injury to the lateral femoral cutaneous nerve.

Hip arthroscopy for challenging deformities: global pincer femoroacetabular impingement

Pincer femoroacetabular impingement occurs in focal or global forms, the latter having more generalized and typically more extreme acetabular overcoverage. Severe global deformities are often treated with open surgical dislocation of the hip. Arthroscopic technical challenges relate to difficulties with hip distraction; central-compartment access; and instrument navigation, acetabuloplasty, and chondrolabral surgery of the posterior acetabulum. Techniques addressing these challenges are introduced permitting dual-portal hip arthroscopy with central-compartment access, subtotal acetabuloplasty, and circumferential chondrolabral surgery. The modified midanterior portal in combination with a zone-specific sequence of acetabular rim reduction monitored with fluoroscopic templating enables precision subtotal acetabuloplasty. Guidelines for acetabular rim reduction include the following suggested radiographic endpoints: postoperative center-edge angle of 35°, a neutral posterior wall sign, and an anterior margin ratio of 0.5. Arthroscopic zone-specific chondrophobic rim preparation and circumferential labral reparative and reconstructive techniques and tools permit the arthroscopic treatment of these challenging deformities.

Hip arthroscopy: prevalence of intra-articular pathologic findings after traumatic injury of the hip

PURPOSE

The purpose of this study was to document and compare the incidence of intra-articular hip pathologic findings identified using arthroscopy versus conventional imaging in patients with acute trauma to the hip.

METHODS

This was a blinded prospective case series study designed to review the incidence of intra-articular pathologic disorders in patients with post-traumatic injury between the ages of 18 and 65 years who were referred to a single surgeon. Injuries included hip dislocation, proximal femur fracture, pelvic ring fracture, acetabular fracture, penetrating injury (gunshot wound), and soft tissue injury. Preoperative radiographs, computed tomographic (CT) scans, or magnetic resonance imaging/magnetic resonance angiography (MRI/MRA) scans (or a combination of these) were obtained. Findings were documented and compared with intraoperative findings.

RESULTS

A total of 29 post-traumatic hips were enrolled in this study. Hip arthroscopy identified 17 of 29 hips (59%) as having loose bodies, 11 of 29 (38%) hips as having an intra-articular step deformity, 14 of 29 (49%) hips as having an osteochondral lesion, and 27 of 29 (93%) hips as having a labral tear. Plain radiographs and CT scans yielded low sensitivity when compared with arthroscopy for the identification of loose bodies and step deformities. MRI/MRA comparison with arthroscopic findings suggest that MRI/MRA is an accurate tool for identification of labral tears, because 91% of tears seen on arthroscopy were also identified by MRI/MRA. In 4 hips, however, MRI/MRA failed to identify osteochondral lesions that were subsequently identified by arthroscopy.

CONCLUSIONS

Traumatic injuries of the hip result in substantial intra-articular pathologic findings, including loose bodies, labral tears, step deformities, and osteochondral lesions. The arthroscope is a powerful tool in identifying these injuries. Plain radiographs and CT scans appear to underestimate the true incidence of loose bodies and step deformities within the joint when compared with hip arthroscopy after a traumatic injury of the hip.

LEVEL OF EVIDENCE

Level IV, diagnostic case series.

Arthroscopic osteosynthesis of femoral head malunion

We present the case of a femoral head malunion with lateral cephalic femoroacetabular impingement managed by arthroscopic osteotomy/takedown, bone grafting, internal fixation, and cephaloplasty. The treatment rationale and surgical technique are presented. A successful outcome at 3 years was obtained with radiographic evidence of union without osteonecrosis. Even beyond acute femoral head osteosynthesis, arthroscopic surgery may enhance the ability to treat femoral head malunions. Moreover, arthroscopic osteosynthesis may address lateral cephalic FAI, a previously unreported condition.

Arthroscopic internal fixation of osteochondritis dissecans of the femoral head

Osteochondritis dessicans of the femoral head is an uncommon problem. Limited literature reports the incidence of osteochondritis dessicans and its treatment. The surgical technique used and outcomes for a 40-year-old man with symptomatic femoral head osteochonditis dissecans who was treated 11 years previously with retrograde drilling and hip arthroscopy are discussed.Despite temporary symptomatic improvement without subchondral collapse after his index procedure, increasing pain a decade later was thought to be caused by a large apical osteochondritic fragment and chondrolabral dysfunction from femoroacetabular impingement. Acetabuloplasty of acetabular overcoverage permitted arthroscopic internal fixation of the bone fragment by improving screw trajectory. Labral refixation and femoroplasty were subsequently performed. At 18-month follow-up, his nonarthritic hip score improved from 53 to 76 and his osteochondritic lesion had healed radiographically.Although clinical improvement with radiographic union has been reported following open screw fixation of femoral head osteochondritis dissecans, to the authors' knowledge this is the first published case with a similar outcome using arthroscopic techniques. Clinical improvement and union of even long-standing osteochondritis dissecans of the femoral head may occur with arthroscopic fragment fixation. Hip arthroscopy may play significant therapeutic and diagnostic roles in the treatment of this condition while offering a less invasive alternative to open osteosynthesis.