Surgical treatment of acetabular fracture

Introduction

Acetabular fracture is one of the most complex injuries treated by orthopaedic surgeon. Now a days this fracture is more commonly seen in young adults as a result of high energy road traffic accident and thus surgical treatment of this fracture is more commonly indicated now than in the past. Surgical treatment of acetabular fracture is challenging in the sense that surgery is difficult and complication rate is high. Open reduction and internal fixation is the treatment of choice for posteriorly based displaced acetabular fracture.1 Integrity of weight bearing dome of acetabulum is an important prognostic factor. If the fracture crossing dome of the acetabulum remains unreduced posttraumatic degenerative arthritis is inevitable. A displaced fracture (more than 3 mm intra articular displacement either a step or widening) crossing the dome of the acetabulum is an indication of surgery. During surgery Our purpose is to restore anatomical articular congruity by accurate reconstruction of dome of acetabulum, provide adequate coverage of femoral head under reconstructed dome as well as stable and rigid fixation of wall and column to obtain best functional outcome i.e. painless range of motion. For this apart from other things the choice of approach does matter as it requires adequate exposure of acetabulum for accurate fixation of fracture fragments. The Kocher- Langenbeck approach is the most frequently used approach as it provides excellent direct access to the posterior column and posterior wall and indirect access to superior wall and quadrilateral surface.1 This incision is very useful in posterior wall acetabular fracture, posterior column acetabular fracture, posterior column and posterior wall acetabular fracture, transverse and posterior wall acetabular fracture, transeverse actabular fracture with major displacement occurring at posterior column and posterior element reduction and fixation in T type acetabular fracture.

Aim of the Study

To evaluate functional outcome and complications of surgical treatment of displaced acetabular fracture using Kocher Lengenbec approach for internal fixation.

Material and Methods

This is a prospective study conducted by author during 2004 to 2019. Our series consisted of twenty-four patients of posterior acetabular fractures treated surgically using Kocher- Langenbeck approach. According to Letournel judet classification there were 11 posterior wall fracture, 3 posterior column fracture, 5 transverse fracture, 2 posterior column and posterior wall fracture and 3 transverse and post wall fracture in the series. Patient counselling and informed consent was mandatory in our series. Mean age of the patient was 38.58 years (range 30 to 45 years) with standard deviation of 3.67 and variance 13.49. Patients were more frequently male (n=18 i.e. 75%) than female (n=6 i.e.25%). All of them were investigated for their fitness for spinal or epidural block or general anaesthesia. Steps of the procedure including patient positioning, surgical procedure, provisional fixation and definitive fixation were discussed and documented. Radiographic evaluation included x-ray A-P View of pelvis, Obturator oblique view and Iliac oblique view and CT scan with or without 3D reconstruction. Five (20.83%) patients had posterior dislocation or subluxation of femoral head visible on first x-ray that was reduced within 6 hours under fluoroscopic control and held in distal femoral traction. The mean injury to operation interval was 7 days (range 3 to 15 days). Four patients (16.66%) were having sciatic nerve injury preoperatively. In our Series out of 24 patients 12 patients were operated in lateral position and 12 patients were operated in prone position with ipsilateral distal femoral traction. Incision used was Kocher -Langenbeck with and without trochanteric osteotomy as per need.

Surgical Procedure

Either spinal or epidural block was used during the procedure. Either Lateral or prone position was used on fracture table with radiolucent top. Draping was carried out after proper antiseptic scrub. In all 24 cases Kocher -Langenbeck incision was used and standard operative technique was followed. Ipsilateral knee was kept flexed to 80 to 90 degree during the procedure to avoid tension on sciatic nerve. Reconstruction of posterior column was followed by reconstruction of posterior wall in order to ensure accurate reconstruction of articular surfaces, stable fixation of column and wall to provide adequate Coverage of femoral head under reconstructed dome. Reconstruction of posterior column was carried out with contoured reconstruction plate or lag screw. Reconstruction of posterior wall was done with interfragmentary screw or with reconstruction plates or one third tubular plate or locking plate in buttress mode. In all cases combination of implants were used. Intraoperative fluoroscopy was used as per need. Any incarcerated fragment was removed and femoral head is relocated. Stability was assessed by entire range of motion of hip intraoperatively. Wound was closed over drain in layers. Final fluoroscopic check was done at conclusion of the procedure.

Postoperative Care

In immediate post-operative period the operated limb was supported on Brown Bohler splint. Limb elevation was ensured. First dressing change was done on third postoperative day and drain was removed at the same time. Sutures were removed on 14^th day. On 5^th postoperative day gentle range of motion exercises were started at knee and ankle.

Follow UP

Patients were followed up at 2 weeks, 4 weeks, 6 weeks, 8 weeks, regularly at 6 week interval for 6 months and then at 3 month interval for next 1.5 years. Radiographic analysis (AP pelvis, obturator and Iliac oblique) was performed at each follow up. Final followup radiographs were graded according to criteria developed by Matta. Excellant denotes a normal appearing hip joint, Good as mild changes with minimal sclerosis and joint narrowing, Fair indicates intermediate changes with moderate sclerosis and joint narrowing (<50%) and Poor signify advanced changes. Functional outcome was assessed by Harris Hip Score.

The peroneal division was more commonly involved than tibial division. Most of the patient recovered within six months of operation. No mortality was seen in our series.

Figure 1

Case 1: Preoperative

Figure 2

Case 1: Postoperative

Figure 3

Case 2: Preoperative

Figure 4

Case 2: Postoperative

Figure 5

Case 3: Preoperative

Figure 6

Case 3: Preoperative

Figure 7

Case 3: Postoperative

Observation

Mean length of hospital stay was 16 days (length 11 to 30 days). Reduction was assessed by x-ray using Matta criteria on third or fourth postoperative day and functional outcome was graded using Harris Hip Score and Merle d Aubigne and Postel modified by Matta criteria as Excellent, Good, Fair and Poor. Main elements followed were pain, walking and range of hip motion. Poor result was noted in the patient with poor reduction (more than 10mm separation) postoperatively. There was statistically significant correlation between quality of reduction and clinical outcome (p<.001).

Disscussion

Open reduction and internal fixation is the treatment of choice for most of the posteriorly based displaced acetabular fracture.2, 3, 4, 5, 6 Moed BR (3) in his study reported good reduction and functional out come in posteriorly based acetabular fracture using Kocher- Lengenbeck approach.

Poor fracture reduction, multi-fragmentary fracture of posterior wall, transverse multi-fragmentary fractures of tectum or roof of acetabulum, cartilage damage to the femoral head and or acetabulum(marginal impaction), fractures associated with hip dislocations, undue delay in surgery (>15 days) and initial fracture displacement more than 10 mm are associated with poor prognosis. Positive outcomes correlated with radiographic outcomes. Worst result was seen in the patients with posterior column /posterior wall followed by transverse /posterior wall trans-tectal fracture. Despite relatively large numbers of complications, surgical treatment of acetabular fracture offers better result than conservative treatment.7 Kocher- Lengenbeck approach provides sufficient access to the majority of posterior based acetabular fracture.7 There was a statically significant correlation between the quality of reduction and clinical result (p<0.001). Fracture type and cartilage damage, sex, and age are prognostic factors for outcome after open reduction and internal using Kocher - Lengenbeck approach. The most important factor predictive of good functional outcome is anatomic reduction of fracture (less than 1 mm of displacement). O Alexa RI Malancea et al.7 in his study reported excellent result in 23.7%, Good in 60.5%, fair in 10.5% and poor in 5.3%. He observed heterotropic ossification as most frequently encountered complication. Heterotopic ossification was the most frequent complication in my series also and Indomethacin was used postoperatively in those cases. Pol Maria Rommenns8 in his study of 60 patients of posterior wall acetabular fracture reported 69.6% excellent or good result using the Kocher-Langenbeck approach.

Conclusion

The Kocher –Langenbeck approach is an ideal approach for posteriorly based acetabular fracture and the results and complications encounterd are with in acceptable limit.

Source of Funding

None.

Conflict of Interest

The authors declare no conflict of interest.