Introduction■ Generally caused by high energy trauma■ Such high energy injuries usually have a high incidence of major associated injuries■ The fracture or fracture dislocation produced depends on the magnitude and the direction of the injuring force as well as on the strength of the bone.
Acetabulum - Anatomy■ Incomplete hemispherical socket with an ♦ inverted horse-shoe shaped articular surface ♦ non articulating cotyloid fossa.■ The articular surface is composed of and supported by two columns of bone (described by Letournel and Judet) as an inverted ‘Y’
Acetabulum – Anatomy ‘The Column Concept’■ Used in the classification of the fractures■ The anterior column ♦ Iliac crest, iliac spines, the anterior half of the acetabulum and the pubis.■ The posterior column ♦ Ischium, ischial spine, posterior half of the acetabulum and the dense bone forming the sciatic notch■ The shorter posterior column ends at its intersection with the anterior column at the top of the sciatic notch
Acetabulum - Anatomy■ The dome or roof is the weight bearing portion of the articular surface that supports the femoral head■ The quadrilateral surface is the flat plate of bone forming the lateral border of the pelvic cavity■ The iliopectineal eminence is the prominence in the anterior column that lies directly over the femoral head.
Acetabulum – Anatomy Neurovascular structures■ The sciatic nerve■ The superior gluteal Artery and Nerve■ Corona mortis
Classification (Letournel and Judet)■ Simple fractures ♦ fractures of the posterior wall, posterior column, anterior wall, anterior column and transverse fractures.■ Associated fractures ♦ T-shaped fractures, fractures of the posterior column and posterior wall, transverse + posterior wall fracture, anterior fracture + hemitransverse posterior fracture and both column fracture.
Classification Comprehensive Classification after Letournel■ TYPE A - PARTIAL ARTICULAR ONE COLUMN FRACTURE ♦ A1—Posterior wall ♦ A2—Posterior column ♦ A3—Anterior wall and/or anterior column
Classification Comprehensive Classification after Letournel■ TYPE B PARTIAL ARTICULAR TRANSVERSE ORIENTED FRACTURE - Transverse types with portion of the roof attached to intact ilium ♦ B1—Transverse + posterior wall ♦ B2—T types ♦ B3—Anterior with posterior hemitransverse
Classification Comprehensive Classification after Letournel■ TYPE C COMPLETE ARTICULAR, BOTH COLUMN FRACTURE - both columns are fractured and all articular segments, including the roof, are detached from the remaining segment of the intact ilium, “the floating acetabulum.” ♦ C1—Both column—anterior column fracture extends to the iliac crest (high variety) ♦ C2—Both column—anterior column fracture extends to the anterior border of the ilium (low variety) ♦ C3—Both column—anterior fracture enters the sacroiliac joint
Classification Comprehensive Classification after Letournel■ Qualifiers: Additional information can be documented concerning the condition of the articular surfaces to further define the prognosis of the injury. The information should be, as additional qualifiers, identified by Greek letters. ♦ a1) Femoral head subluxation, anterior ♦ a2) Femoral head subluxation, medial ♦ a3) Femoral head sublucation, posterior ♦ b1) Femoral head dislocation, anterior ♦ b2) Femoral head dislocation, medial ♦ b3) Femoral head dislocation, posterior ♦ g1) Acetabluar surface, chondral lesion ♦ g2) Acetabular surface, impacted ♦ d1) Femoral head, chondral lesion ♦ d2) Femoral head, impacted ♦ d3) Femoral head, osteochondral fracture ♦ e1) Intra-articular fragment requiring surgical removal ♦ f1) Nondisplaced fracture of the acetabulum
Acetabular anatomyPosterior wall with posterior Posterior wall fracture with a column fracture transverse fracture
Acetabular anatomySuperior dome fracture Transverse fracture
Acetabular anatomyT-type fracture Anterior wall fracture with dislocation
Signs and symptoms■ Apart from local examination ♦ Look out for associated life threatening injuries (intra-abdominal injuries) ♦ A, B, C first before the rest ♦ Older patients ◘ Arrhythmia, transient ischemic attacks may have led to the fall ♦ SDH can occur when older patients fall.
Radiographic Evaluation■ Requires ♦ A CT scan ♦ 3 plain radiographic views ◘ Antero-posterior view of the hip ◘ 45° iliac oblique view ◘ 45° obturator oblique view Judet view 45° oblique view
Plain Radiographs 1 - AP View■ Start evaluation with this view■ Iliopectineal line – represents the anterior column; Ilioischial line – represents the posterior column; Posterior lip – represents the posterior wall; Anterior lip – represents the anterior wall; Dome; Tear-drop
Plain Radiographs 2 - The obturator oblique view■ Anterior column fracture displacements■ Posterior wall fragments and their displacement
Plain Radiographs 3 - The iliac oblique view■ Posterior border of the posterior column and■ Continuity of the true posterior column can be determined.
CT Scan■ 3 mm interval axial cuts■ Include the entire pelvis to avoid missing a portion of the fracture■ Compare with opposite hip Watch for Anterior and posterior wall fragments, marginal impaction, retained bone fragments in the joint, comminution, presence or absence of a dislocations and any sacroiliac joint pathology.
Management■ Initial treatment – follow ATLS protocols■ Operative treatment of acetabular fractures are usually not performed as an emergency■ Normally, a closed reduction Skeletal traction■ Even a rare true central dislocation is treated that way
Operative Surgical anatomy■ Posterior wall fragments ♦ vary in the size and degree of comminution ♦ Well appreciated in a CT scan. ♦ Unrecognized fracture lines maybe detected at surgery ♦ So the posterior wall fracture should never be fixed with lag screw alone. ♦ The posterior wall fragment receives its blood supply from the capsule avoid detaching the capsule from its blood supply.
Operative Surgical anatomy■ Posterior Column fractures ♦ Can occur anywhere along the posterior column from the ischial spine to the sciatic notch. ♦ Typically, the column fragment rotates. ♦ It is necessary to derotate the fragment and check the reduction.
Operative Surgical anatomy■ Anterior Column fractures ♦ Occur at various levels along the anterior column. ♦ Although the pubic ramus is part of the anterior column, ramus fracture usually indicates the presence of a pelvic fracture rather than an acetabular fracture.
Operative Surgical anatomy■ Transverse fractures ♦ Run across the acetabulum. ♦ The fractures that cross the region of the fovea are called infratectal. ♦ The fractures that cross just above the fovea are juxtatectal ♦ fractures crossing higher are transtectal.■ T-type fractures ♦ Transverse fracture with a fracture line seperating the anterior column from the posterior column
Operative Surgical anatomy■ Anterior and posterior hemi-transverse fractures ♦ This is an anterior column fracture with and additional fracture line that runs transversely across the posterior column. ♦ Here, the displacement is usually anterior and the posterior column not significantly disturbed. ♦ Thus reducing the anterior column usually reduces the posterior column.
Operative Surgical anatomy■ Both column fractures ♦ Entire acetabulum is separated from the axial skeleton. ♦ Sometimes, it is called as a floating acetabulum. ♦ Since the entire acetabulum is separated from the ilium, the actual joint can appear congruent. ♦ This radiographic appearance is called the secondary congruence. ♦ Spur sign
Spur sign■ Pathognomonic of both column fratures. see in obturator oblique view
Indications for non-operative treatment■ Non displaced and minimally displaced fratures.■ Fractures that traverse the wt bearing dome, but with less than 2 mm displacement – managed by non wt bearing and or skeletal traction for 8 weeks.■ Secondary congruence in displaced both column fractures.■ Closed treatment gives good results.
Indications for non-operative treatment■ Fractures with significant displacement but, in which the region of the joint involved is judged to be unimportant prognostically.■ This can be determined by the roof arc measurement described by Matta and Olson as 45 degrees for each roof arc, medial, anterior and posterior.■ Another roof arc measurement as proposed by Vrahas, Widding and Thomas is 25 degree fro the anterior roof arc, 45 degree of the medial roof arc and 70 degree for the posterior roof arc.■ Most authors agree that displaced fractures through the weight bearing dome should be treated with ORIF, regardless of how they ‘line up’ in traction.
Medical contraindications to surgery■ Multisystem injury■ An open wound in the anticipated surgical field The Morel – Lavallée lesion■ Presence of a suprapubic catheter is a contraindication for ilioinguinal approach.■ Elderly patients with osteoporotic bone – where ORIF may not be feasible.
Indications for operative treatment■ In fracture incongruity due to ♦ Posterior column or wall injuries ♦ Displaced fractures of the superior dome ♦ Retained bony fragments■ In the limb ♦ Sciatic nerve injury ♦ Fracture of the ipsilateral femur ♦ Injury to the ipsilateral knee■ In the patient – polytraumatised patient
Treatment of specific fracture patterns■ Posterior wall fractures ♦ Posterior Langenbeck approach with the patient positioned either prone or lateral using lag screw and a reconstruction plate placed from the ischium over the retro acetabular surface onto the lateral ileum. (If the fracture extends superiorly into the dome, a trochanteric osteotomy may be performed to allow additional exposure) ♦ To avoid AVN of the posterior wall, the posterior wall fragments must not be detached from the posterior capsule. The knee must be kept flexed throughout the procedure to avoid injury to the sciatic nerve.
Treatment of specific fracture patterns■ Posterior column fracture ♦ Though uncommon if significantly displaced, requires ORIF (Kocher Langenbeck approach). ♦ Typical fixation is with a lag screw combined with a contoured reconstruction plate along the posterior column. ♦ Rotational deformity must be corrected by placing a Shanz screw in the ischium to control rotation while the fracture is reduced with a reduction clamp
Treatment of specific fracture patterns■ Anterior wall and anterior column fracture ♦ Isolated anterior wall fractures are uncommon. ♦ Sometimes, they are associated with anterior hip dislocation. ♦ Fractures requiring surgery are fixed with a buttress plate applied through an ilioinguinal or iliofemoral approach. ♦ Anterior column fractures are approach similarly with fixation by a contoured plate along with a pelvic brim.
Treatment of specific fracture patterns■ Transverse fractures ♦ Transtectal fractures have the worst prognosis and accurate reduction is essential. ♦ Juxtatectal fractures also usually require reduction. ♦ Typical reduction is through a posterior approach using a Farabeuf clamp to reduce the fractures while rotation is controlled by a Shanz screw in the ischium. ♦ Posterior fixation typically is with a buttress plate along the posterior column and anterior fixation using a 3.5 mm lag screw placed into the anterior column from a position above the acetabulum.
Treatment of specific fracture patterns■ Posterior Column fracture with associated posterior wall fracture ♦ A Kocher-Langenbeck approach is used with or with out a trochanteric osteotomy. ♦ The column fracture is reduced first. ♦ A short reconstruction plate is placed posteriorly along the posterior edge of the column. A separate plate is used for the wall fragment. ♦ T screws through the plate secure rotational reduction on the posterior column fragment.
Treatment of specific fracture patterns■ Transverse fracture with associated posterior wall fracture ♦ The common fracture can be difficult to reduce. ♦ The posterior wall component requires a posterior exposure, but reduction of the anterior part of the transverse fracture can be difficult through a Kocher-Langenbeck approach and extensile or combined approach is frequently necessary.
Treatment of specific fracture patterns■ T-type and anterior column-posterior Hemi- transverse fracture ♦ They are treated through an ilioinguinal approach with a contoured plate placed along the pelvic brim and lag screws extending into the posterior column. ♦ For a T-type fracture with severe posterior displacement but minimal anterior displacement, posterior approach alone may be sufficient with placement of anterior column lag screw. ♦ If both the anterior and posterior components of the fracture are significantly displaced, an extensive or combined approach are required.
Treatment of specific fracture patterns■ Both column fractures ♦ These have varying degrees of comminution and can be extremely complex and difficult to treat. ♦ Many both column fractures can be treated through an anterior ilioinguinal approach. ♦ But a posterior or extensile exposure is required for involvement of the sacroiliac joint, significant posterior wall fracture, or intraarticular comminution. ♦ Reduction is begun from the most proximal portion of the fracture and proceed towards the joint.
Post-operative care■ Closed suction drain■ Antibiotic for 48 – 72 hours■ Passive motion of the hip on the 2nd or 3rd day.■ Touch down ambulation & crutches on 2nd to 4th day.■ The minimal weight bearing status is continued for 8 weeks in patients with simple fractures and 12 weeks in most others.■ Rehabilitation of the abductor muscle group is needed.
Complications■ General ♦ Thromboembolic disease ♦ Infection■ Specific
Specific Complications■ Sciatic nerve injury ♦ Thirty percentage of acetabular fractures have associated sciatic nerve injury. ♦ In 2 – 6 % of patients, it occurs as a result of surgery and is more often associated with posterior fracture pattern treated through a Kocher-Langenbeck and extensile exposures. ♦ The peroneal component of sciatic nerve is more often involved than the tibial component. ♦ Complete peroneal palsies have the worst prognosis. Tibial component has greater chances of recovery.
Specific Complications■ Other nerves ♦ Femoral nerve injury – though rare, care to be taken during the anterior ilioinguinal approach. ♦ Superior Gluteal nerve injury is vulnerable in the greater sciatic notch, resulting in abductor paralysis. ♦ Pudendal nerve injury ♦ Injury to the lateral femoral cutaneous nerve causes sensory loss in the lateral aspect of the thigh.
Specific Complications■ Post-traumatic arthritis■ Heterotopic ossification■ Chondrolysis■ AVN