Rare posterior wall acetabular fracture extending to iliac crest managed via extended iliofemoral approach: A case report

Abstract

Case

A 27-year-old male sustained a posterior wall acetabular fracture with proximal extension into the iliac crest, a variant not encompassed by the Letournel–Judet classification. The injury was managed with an extended iliofemoral approach in the supine position. Fixation included a reconstruction plate for the iliac blade and lag screws.

Conclusion

Posterior wall fractures with iliac crest extension are exceedingly rare and unclassified. The extended iliofemoral approach provided single-incision exposure, enabling anatomic fixation and excellent 2-year functional outcome.

Introduction

Acetabular fractures are relatively uncommon, accounting for 5%–8% of all fractures and approximately 10% of pelvic fractures [1], typically occurring in young adults after high-energy trauma and are associated with significant morbidity due to their intra-articular nature [2]. Epidemiological studies suggest that incidence is increasing, particularly among elderly patients, in whom low-energy falls predominate [3].

The classification of acetabular fractures has evolved, beginning with the early descriptive efforts of Judet and later refined by Letournel, whose system remains the foundation of modern management [4], [5]. The Letournel–Judet classification provides a framework that links fracture morphology to surgical approaches. Subsequent studies have shown that up to one-third of acetabular fractures do not conform to their elementary or associated patterns, reflecting the complexity of acetabular injury mechanisms [6]. Importantly, even Letournel's comprehensive scheme fails to encompass certain transitional morphologies such as posterior wall fractures with proximal extension into the iliac blade and crest, making such variants diagnostically challenging and surgically demanding.

It is important to emphasise how this case diverges from the Letournel–Judet classification. In the classical system, posterior wall fractures are confined to the rim and posterior column; in contrast, this case demonstrated proximal propagation into the iliac blade and crest, an extra-acetabular extension not accounted for in the classification. This underscores the limitations of this scheme when faced with transitional morphologies.

This is a case of a young adult male with a rare posterior wall acetabular fracture successfully managed using an extended iliofemoral approach, which enabled comprehensive exposure and stable fixation.

Statement of informed consent

The patient was informed that data concerning the case would be submitted for publication, and consent was obtained.

Case report

A 27-year-old male was admitted to a tertiary care trauma centre following a high-energy road traffic accident. He presented with severe pain in the left groin and inability to bear weight. The Advanced Trauma Life Support (ATLS) protocol was followed.

Radiographs and computed tomography scans revealed a posterior wall acetabular fracture propagating proximally through the iliac blade into the iliac crest (Fig. 1: A, B, C,D). There were no associated injuries or neurovascular deficits.

Fig. 1.

Preoperative radiology, A- Anteroposterior plain radiograph; B- Coronal section of CT scan; C- 3D CT scan showing fracture line from posterior wall extending into iliac blade and crest.

Although the hip appeared concentric radiographically, the posterior wall–iliac crest fragment was grossly unstable and carried the risk of secondary displacement under physiological loading. Surgical stabilisation was indicated to restore columnar continuity, prevent late instability, and allow early mobilisation.

Definitive fixation was performed on day three after resuscitation. The patient was positioned supine, and an extended iliofemoral approach was utilised. The incision was made along the iliac crest, curving anteriorly toward the ASIS (Anterior Superior Iliac Spine) and distally onto the lateral thigh.

Subperiosteal dissection exposed the iliac crest and outer table. An ASIS osteotomy was performed to improve mobilisation of the sartorius and tensor fascia lata as a sleeve (Fig. 2), thereby enhancing anterior retraction and visualisation of the iliac wing and acetabular dome. This step also permitted a controlled iliacus slide from the inner table, improving access to the supra-acetabular corridor for screw placement. This exposure allowed for the retraction of soft tissues sufficiently to visualise both the iliac crest and acetabular margins without excessive stripping.

Fig. 2.

Schematic 3D sequence of extended iliofemoral approach with ASIS osteotomy, soft-tissue reflection, iliacus slide, and fixation using plate and lag screws.

The posterior wall fragment was continuous with the iliac blade; therefore, indirect reduction was achieved through anatomical alignment of the iliac blade proximally and distally with pointed reduction clamps. After provisional reduction was confirmed fluoroscopically, a precontoured 3.5-mm reconstruction plate was applied along the iliac blade to compress the proximal extension.

Two 6.5-mm partially threaded cancellous screws were placed as lag screws in the supra-acetabular corridor. The entry point was chosen just above the rectus femoris attachment at the AIIS, above the acetabular rim, directed medially and slightly inferiorly to capture the posterior fragment. To avoid intra-articular penetration, fluoroscopy was used in anteroposterior, obturator oblique, and iliac oblique projections, and a depth gauge confirmed the trajectory before final screw insertion. ASIS osteotomy was fixed with two 3.5-mm cortical screws.

The extended iliofemoral approach is associated with risks of extensive blood loss, soft-tissue stripping, heterotopic ossification, and abductor weakness [7]. To minimise these, meticulous subperiosteal dissection was employed, muscle release was limited to what was strictly necessary, and closure was performed in layers. Indomethacin prophylaxis was given postoperatively to reduce the risk of heterotopic ossification.

Reduction and implant position were confirmed fluoroscopically in anteroposterior, obturator oblique, and iliac oblique views (Fig. 3). Hip stability was satisfactory on intraoperative testing.

Fig. 3.

Intraoperative fluoroscopy images confirming reduction and fixation.

During the postoperative course, toe-touch weight-bearing was initiated on day two, progressed at six weeks. At six months, radiographs confirmed union (Fig. 4). At two years, the patient was pain-free, had symmetrical hip motion, and returned to pre-injury activity (Fig. 5). The Harris Hip Score was 96, with no evidence of arthritis or heterotopic ossification.

Fig. 4.

Postoperative radiographs at six-month follow-up showing union and congruent reduction.

Fig. 5.

Two-year clinical follow-up with full, painless hip motion.

Discussion

Posterior wall fractures are the most common acetabular subtype; however, proximal extension into the iliac blade and crest is exceedingly rare and not captured in the Letournel–Judet classification [4], [5]. Baumgaertner defined posterior wall fractures as confined to the posterior rim and articular surface, without iliac crest involvement [8]. In a typical posterior wall acetabular fracture, the fracture line originates at the posterior rim and propagates obliquely into the posterior column, often exiting near the greater sciatic notch. The fracture is usually confined to the acetabulum and posterior column, with occasional inferior extension toward ischium but rarely beyond the acetabular dome.

Richards et al. reported a pure superior wall acetabular fracture, a rare morphology that mimicked a posterior wall fracture radiographically but was fundamentally different [9]. In this pattern, the fracture line originated in the superior acetabular dome and extended cranially toward but not fully into the iliac crest. Importantly, the posterior rim was not the primary site of injury; rather, the dome fragment compromised femoral head containment. This created a transitional configuration between posterior wall and anterior column fractures, where stability was determined by superior articular surface rather than posterior border.

Trikha et al. analyzed posterior wall variants with cranial propagation [10]. These fractures began as typical posterior wall patterns but extended upward toward the superior acetabular rim. While the posterior articular margin remained the main fracture element, the superior extension limited visualisation and fixation through standard Kocher–Langenbeck exposures. The authors highlighted technical difficulty of achieving stable fixation when fracture line ascended toward dome, sometimes requiring extended approaches or modified fixation strategies.

Desauge et al. described an atypical three-column roof fragment [11]. In this rare configuration, an isolated articular fragment of the acetabular roof was separated but tethered to all three columns. Unlike posterior wall or column injuries, this fragment behaved independently, demanding fixation strategies that restored dome congruence with simultaneous column-to-roof stabilisation. These injuries required combined surgical windows or extended approaches to achieve anatomic reduction of the dome fragment and preserve hip congruency.

Abdelnasser et al. performed a large analysis of acetabular fractures and reported that nearly 10% of cases remain unclassified under the Letournel system [12]. These included transitional morphologies such as dome-dominant fractures, mixed column-wall combinations, and patterns extending beyond the acetabulum itself. The authors emphasised that such injuries highlight the limitations of rigid classification systems and require individualised surgical planning. Abdelnasser broadly described unclassified fractures; none in their series involved a posterior wall injury with true proximal extension into the iliac crest (Table 1).

Table 1.

Review of literature on rare/unclassified acetabular fracture variants.

Author (year)	Design	Focus / variant	Fracture morphology	Approach / strategy	Outcomes	Key takeaway
Trikha et al., 2020 (Eur J Orthop Surg Traumatol)	Retrospective series (7/63 PW fractures)	Posterior wall variants	Fragments displaced anterosuperior/anterocentral/anteroinferior to femoral head	Kocher–Langenbeck; some needed trochanteric flip or surgical dislocation	5/6 good–excellent results; 1 arthritis requiring THA	PW variants exist; cranial/atypical extension complicates exposure and fixation
Richards et al., 2021 (JBJS Case Connector)	Single case report	Pure superior wall variant	Dome fragment extending cranially toward iliac crest; rim intact; transitional PW–anterior column	Dome-focused fixation; exposure tailored to dome	Satisfactory short-term	Superior dome variant may be under-recognized; stability dictated by dome not rim
Desauge et al., 2022 (Orthop Traumatol Surg Res)	Retrospective review (534 fractures; 96 both-column analyzed)	Independent acetabular roof fragment (‘three-column’)	Type 1: posterosuperior roof fragment; Type 2: isolated roof fragment separated by juxtatectal line	Combined anterior + posterior in displaced cases	Best results when fragment minimally displaced; reduction quality critical	Recognition of roof fragment subtypes vital for approach choice
Abdelnasser et al., 2024 (Eur J Orthop Surg Traumatol)	Retrospective (235 patients; 22 unclassified)	Existence of unclassified fractures	Dome-dominant, mixed column-wall, quadrilateral plate, rim-labral avulsion, impaction	No fixed protocol; highlighted need for modifiers	Not outcome-focused	~10% of acetabular fractures cannot be classified; require tailored planning
Present Case (2023)	Single case report	Posterior wall with iliac crest extension	Posterior wall fracture propagating proximally into iliac blade and crest (extra-acetabular continuity)	Extended iliofemoral approach in supine position; iliac blade plated, posterior wall fixed with lag screws	Union at 6 months; pain-free, Harris Hip Score 96 at 2 years	First reported case of PW fracture with true iliac crest extension; required simultaneous acetabular + iliac fixation via single-incision extended iliofemoral approach

In contrast, this case demonstrated a posterior wall fracture that propagated proximally beyond the acetabular margin into the iliac blade and crest. This extra-acetabular extension represents a unique morphology not previously described, necessitating fixation of both acetabular and iliac components in continuity through an extended iliofemoral approach (Table 2).

Table 2.

Comparison of posterior wall and rare variants of acetabular fractures.

Type	Fracture propagation pattern	Key references
Typical posterior wall fracture	Begins at posterior rim → propagates obliquely into posterior column; confined to acetabulum, sometimes extending inferiorly toward ischium. Rarely extends superiorly beyond dome. Often associated with posterior dislocation.	Judet & Letournel [4], [5]; Baumgaertner [7]
Posterior wall with cranial propagation	Posterior rim fracture line extends superiorly into acetabular dome, but contained within acetabulum. Visualisation and fixation difficult with standard KL approach.	Trikha et al. [9]
Pure superior wall fracture	Fracture originates in superior acetabular dome with incomplete extension toward iliac crest. Posterior rim minimally involved. Represents a transition between posterior wall and anterior column.	Richards et al. [8]
Three-column roof fragment	Independent articular roof fragment separated but tethered to multiple columns; not a wall/column fracture per se. Requires combined exposures for fixation.	Desauge et al. [10]
Unclassified acetabular variants	Transitional morphologies (~10% of cases) that defy Letournel system. Includes unusual dome/roof patterns and complex wall-column mixes.	Abdelnasser et al. [11]
Our case (posterior wall with iliac crest extension)	Posterior wall fracture originating at rim, propagating proximally beyond acetabulum into iliac blade and crest — an extra-acetabular extension not previously reported. Requires fixation of both acetabular and iliac components in continuity.	Present case

The Kocher–Langenbeck approach provides excellent exposure for posterior wall fractures [13]. For cranial extension, Siebenrock et al. described the trochanteric flip osteotomy [14], and Ganz et al. surgical dislocation [15]. However, these techniques remain acetabulum-focused and are inadequate for fractures extending into the iliac crest.

Functional outcome in acetabular fractures depends heavily on anatomic reduction and fixation stability. Matta showed improved results when the reduction was performed within three weeks [2]. Moed et al. and Saterbak et al. further demonstrated the impact of initial stability and morphology on long-term success [16], [17]. Posterior wall fractures with associated dislocation portend worse outcomes [18]. This patient's congruent hip likely contributed to recovery. Long-term studies confirm durable results with accurate reduction and stable fixation, even in complex patterns [19], [20].

Conclusion

Compared with previously described rare variants such as pure superior wall fractures, cranial posterior wall extensions, and roof fragment patterns, this case represents a unique posterior wall fracture with true proximal extension into the iliac crest. Recognition of this morphology justified deviation from the standard posterior approach. The extended iliofemoral approach allowed comprehensive exposure, stable fixation, and excellent two-year functional outcome. This report highlights the need to tailor surgical strategy to fracture anatomy rather than rely solely on classification.

CRediT authorship contribution statement

Deepak Kumar: Conceptualization, Data curation, Supervision, Visualization. Sai Surya Dinesh Pydi: Writing – original draft, Writing – review & editing, Visualization, Resources, Methodology. Arjit Bansal: Validation, Visualization, Supervision, Writing – original draft, Writing – review & editing. Tarkik Thami: Supervision, Validation. Aduri Tharun Teja: Methodology, Writing – review & editing. Utkarsh Kumar Reddy Gopavaram: Writing – review & editing, Resources, Methodology.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.