Transverse Acetabular Fracture ORIF

Indications. Operative fixation is offered for a transverse acetabular fracture when the weight-bearing dome is involved or the hip is incongruous. - Absolute indications: displaced transverse fracture with greater than 2mm articular step or gap involving the weight-bearing dome; an incongruous hip joint (femoral head not concentric with an intact dome); a roof arc angle less than 45 degrees on any view (medial, anterior or posterior) indicating dome involvement; an associated posterior wall fracture causing posterior instability; an open fracture; an irreducible fracture-dislocation or an intra-articular fragment blocking reduction.

• Relative indications: 2mm displacement in a young, active patient; quadrilateral plate medialization causing hip incongruity; an associated T-type or posterior-wall component; a failed or unacceptable closed reduction in a low transverse pattern; a progressive sciatic nerve palsy after closed reduction (suggests nerve entrapment). Contraindications. - Absolute contraindications: severe medical comorbidities precluding a 2-3 hour operation; active sepsis or a local skin infection; a moribund patient.
• Relative contraindications: severe osteoporosis (relative — may need buttress plating); a low-demand elderly patient with an infratectal fracture; a non-ambulatory patient; delayed presentation greater than 21 days (consider acute total hip arthroplasty); marginal soft tissues such as a Morel-Lavallée lesion (delay surgery). Deciding to operate — the roof arc rule (Matta 1986). On each of the three standard radiographs a roof arc is measured around the femoral-head centre, and the same threshold of 45 degrees applies to all three. If every arc exceeds 45 degrees (and the CT subchondral arc in the superior 10mm of the dome is intact) the weight-bearing dome is spared and non-operative treatment may be considered; if any arc is less than 45 degrees the dome is involved and operative fixation is indicated. The rule only applies to fracture lines that cross the articular surface (transverse, T-type, anterior/posterior column) — it does NOT apply to posterior-wall or both-column fractures.

Fracture level matters for prognosis. Where the transverse line crosses the dome predicts outcome and feeds into the decision: transtectal (through the weight-bearing dome — worst prognosis, usually operative), juxtatectal (at the dome edge — intermediate), and infratectal (below the dome — best prognosis; many are non-operative if the hip is congruent). Essential workup. - AP pelvis — overall alignment and the six Letournel lines (iliopectineal, ilioischial, teardrop, roof, anterior rim, posterior rim).

• Obturator oblique (45 degrees) — profiles the anterior column and the posterior wall.
• Iliac oblique (45 degrees) — profiles the posterior column and the anterior wall.
• CT with 3D reconstruction — the gold standard for pattern classification, marginal impaction, quadrilateral-plate displacement and intra-articular fragments. Timing. Operate within about 3-7 days of injury once the patient is resuscitated — reduction quality falls with delay. Beyond 21 days, anatomical reduction becomes much less likely; in older patients consider acute total hip arthroplasty. Setup & positioning. Lateral decubitus or prone on a radiolucent table, affected side up, secured with a beanbag or pelvic posts. The leg is draped free so it can be placed in hip extension with the knee flexed to protect the sciatic nerve during retraction. Test ALL fluoroscopy views (AP, obturator oblique, iliac oblique) before draping, and have a cell saver available. Equipment. 3.5mm reconstruction plates (pre-contoured pelvic), 4.5mm cortical screws for column fixation and 3.5mm cortical screws for wall fixation, a spring plate for posterior-wall fragments; pelvic reduction clamps (Farabeuf, Jungbluth, Matta), a ball-spike pusher, Schanz pins for joystick manipulation, Cobb and large Weber clamps; a radiolucent table, vessel loops for nerve protection, and intraoperative fluoroscopy.

The goal is to restore a congruous hip under an intact, anatomically reduced weight-bearing dome. For roughly 70 percent of transverse fractures this is achieved through a single posterior Kocher-Langenbeck approach: expose and protect the sciatic nerve, reduce the unstable inferior ischiopubic fragment to the stable superior iliac segment, plate the posterior column, then drive anterior column lag screws forward from the posterior exposure — Letournel's key contribution that fixes both columns from one incision. The exposure is laid out in full as the first steps below (and in depth on the Kocher-Langenbeck approach to the hip page).

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Postoperative protocol - Touch weight-bearing (10-20kg) for 6 weeks, progressing to full weight-bearing by 12 weeks.

• Range-of-motion exercises begin on day 1-2.
• Posterior precautions for 6-12 weeks if there is any concern about stability.
• VTE prophylaxis: LMWH or a DOAC for 35 days.
• Heterotopic ossification prophylaxis: indomethacin 75mg daily for 6 weeks.
• Radiographs at 6 weeks, 12 weeks, 6 months and 12 months. Complications

Critical danger structures

Letournel's column concept. The acetabulum is formed by two columns: the anterior column (anterior ilium to anterior wall to superior pubic ramus) and the posterior column (posterior ilium to posterior wall to ischium), together forming an "inverted Y". A transverse fracture divides the acetabulum horizontally into a superior segment (iliac wing plus superior dome, attached to the sacrum — STABLE) and an inferior segment (the ischiopubic segment — UNSTABLE, and the fragment that displaces). The weight-bearing dome and the roof arc. The superior acetabular articular surface is the critical weight-bearing zone. Matta's roof arcs (1986) quantify how much intact dome remains around the femoral-head centre, and the CT subchondral arc (the superior roughly 10mm of subchondral bone on axial slices through the dome) corroborates a spared dome. Fractures crossing the dome (transtectal) carry the highest rates of post-traumatic arthritis. The roof-arc rule is valid only for fracture lines through the articular surface (transverse, T-type, anterior/posterior column); it does NOT apply to posterior-wall or both-column fractures. Sciatic nerve anatomy. The sciatic nerve exits the pelvis through the greater sciatic foramen, classically BELOW piriformis (Beaton-Anson type I in about 85-90 percent); variant anatomy (a split nerve, or a division above or through piriformis) occurs in 10-15 percent and must be anticipated. It lies about 20-30mm medial to the posterior acetabular rim as it crosses the posterior column. It is the most commonly injured nerve in acetabular surgery — iatrogenic injury is reported in roughly 2-10 percent, with the peroneal (common fibular) division most vulnerable to traction. Hip extension with knee flexion is the position that relaxes the nerve during retraction. The quadrilateral plate. The thin medial wall of the acetabulum separates the hip joint from the pelvis. It commonly displaces medially in transverse fractures, and that medialization causes hip-joint incongruity even when the columns are reduced. Guidelines, registries and global practice. - Specialist-centre referral (global consensus): displaced acetabular fractures are best managed in dedicated pelvic and acetabular units. UK BOA (BOAST) guidance on pelvic and acetabular fractures, AO Foundation principles and the OTA all advocate early transfer to a high-volume centre, reflecting the surgeon-volume effect seen in the outcome literature.

• Reduction quality as the universal benchmark: across AO, OTA and registry-derived series the operative target is anatomic reduction (ideally a step of 1mm or less, up to 2mm acceptable on the Matta grade), which remains the dominant modifiable determinant of outcome worldwide.
• Arthroplasty registries (NJR England and Wales, AOANJRR Australia, SHAR Sweden, AJRR USA) capture conversion of post-traumatic acetabular fractures to total hip arthroplasty; converted or post-trauma THA consistently shows higher complication and revision rates than primary THA, informing the threshold for acute THA in older patients.
• Resource-stratified practice: in lower-resource settings, late presentation, limited fluoroscopy and intensive-care access shift practice toward fewer extensile approaches and a lower threshold for acute arthroplasty in older patients; the underlying biomechanical and reduction principles are unchanged. Key evidence. Reduction quality is the single controllable predictor of outcome. Matta (1996) showed clinical outcome correlated closely with quality of reduction and that the rate of anatomical reduction fell with complexity, age and delay. The meta-analysis by Giannoudis (2005) pooled 3670 operatively treated fractures and found 75-80 percent excellent or good results at about 5 years, with post-traumatic arthritis the commonest late complication (about 20 percent). Briffa (2011) confirmed durable function at 10 years, and Tannast (2012) reported 79 percent native-hip survivorship at 20 years — anatomic reduction and avoiding extensile exposure protect the native hip, directly supporting single-approach fixation when it is adequate.

1. Letournel E, Judet R. Fractures of the Acetabulum. 2nd ed. Springer-Verlag; 1993. The definitive text on acetabular fracture classification and surgical treatment. 2. Matta JM. Fractures of the acetabulum: accuracy of reduction and clinical results in patients managed operatively within three weeks after the injury. J Bone Joint Surg Am. 1996;78(11):1632-1645. PMID 8934477. 3. Giannoudis PV, Grotz MR, Papakostidis C, Dinopoulos H. Operative treatment of displaced fractures of the acetabulum: a meta-analysis. J Bone Joint Surg Br. 2005;87(1):2-9. PMID 15686228. 3b. Matta JM, Anderson LM, Epstein HC, Hendricks P. Fractures of the acetabulum: a retrospective analysis (roof arc concept). Clin Orthop Relat Res. 1986;(205):230-240. PMID 3698382. 4. Brooker AF, Bowerman JW, Robinson RA, Riley LH Jr. Ectopic ossification following total hip replacement: incidence and a method of classification. J Bone Joint Surg Am. 1973;55(8):1629-1632. 5. Briffa N, Pearce R, Hill AM, Bircher M. Outcomes of acetabular fracture fixation with ten years' follow-up. J Bone Joint Surg Br. 2011;93(2):229-236. PMID 21282764. doi:10.1302/0301-620X.93B2.24056 6. Tannast M, Najibi S, Matta JM. Two to twenty-year survivorship of the hip in 810 patients with operatively treated acetabular fractures. J Bone Joint Surg Am. 2012;94(17):1559-1567. PMID 22992846. doi:10.2106/JBJS.K.00444 7. Kaempffe FA, Bone LB, Border JR. Open reduction and internal fixation of acetabular fractures: heterotopic ossification and other complications of treatment. J Orthop Trauma. 1991;5(4):439-445. 8. Moed BR, Carr SE, Watson JT. Open reduction and internal fixation of posterior wall fractures of the acetabulum. Clin Orthop Relat Res. 2000;(377):57-67. PMID 10943185. doi:10.1097/00003086-200008000-00009 9. Routt ML Jr, Swiontkowski MF. Operative treatment of complex acetabular fractures: combined anterior and posterior exposures during the same procedure. J Bone Joint Surg Am. 1990;72(6):897-904. 10. Tile M, Helfet DL, Kellam JF. Fractures of the Pelvis and Acetabulum. 3rd ed. Lippincott Williams and Wilkins; 2003.