Clinico-radiological outcomes of surgical fixation for posterior column acetabular fractures, with or without posterior wall involvement

Abstract

Background

Posterior column and posterior wall acetabular fractures are associated with hip instability and early development of post traumatic hip arthritis. Literature suggests superior outcomes of isolated posterior column fractures as compared to those involving both posterior column and posterior wall. This study aims to compare functional and radiological outcomes after surgical fixation of posterior column acetabular fractures with or without posterior wall fractures.

Methods

A prospective, comparative study was conducted between July 2017 and July 2022. All skeletally mature patients (>18 years old) with acute (<21 days old), elementary/associated posterior column acetabular fracture and managed surgically were included in the study. Based on the involvement of posterior wall, patients were divided into 2 groups: Group A: without posterior wall fractures; and Group B: with posterior wall fractures. Functional outcomes were calculated using Merle D'Aubingne & Postel criteria and radiological outcomes were assessed using Matta's post-op reduction criteria and Matta's radiographic grading at final follow-up.

Results

There were 32 patients with acetabular fractures involving posterior column without posterior wall (Group A) and 20 patients with posterior wall involvement (Group B). On comparison, patients in Group A had significantly better functional outcomes at 1 year follow-up (p = 0.01). However, there was no significant difference between Matta's Radiographic reduction criteria immediate post-operatively (p = 0.711) and Matta's Radiographic grade at final 1 year follow-up (p = 0.957).

Conclusion

Posterior column acetabular fractures involving the posterior wall have worse functional outcomes and are associated with early failure and post-traumatic arthritis, when treated with fixation of posterior column alone. Future studies should evaluate morphology of posterior wall fragment in the complex fracture patterns, role of its additional surgical fixation and compare it to those with isolated posterior wall fractures.

1. Introduction

Acetabular fractures account for approximately 10 % of all pelvic injuries, with posterior wall fractures being the most prevalent (23.6 %).¹ Displaced fractures and those affecting the weight-bearing acetabular dome necessitate anatomical reduction and internal fixation to maintain articular congruency and prevent early post-traumatic hip arthritis.² The complexity of acetabular fracture fixation is heightened by the challenging learning curve associated with the procedure, the intricate anatomy of the acetabulum, and the complexity of the fracture patterns. Intraoperative patient positioning and the approach to the fracture site is particularly challenging, especially in the context of polytrauma, which is frequently associated with these injuries. As a result, the surgical management of acetabular fractures is considered one of the most demanding tasks for orthopaedic surgeons.³

Posterior column and posterior wall acetabular fractures are complex injuries with significant implications for hip stability and long-term clinical outcomes. Fractures involving both the posterior column and posterior wall tend to be more complex than isolated posterior column fractures. Limited studies have assessed the role of posterior wall integrity in determining functional outcomes and complications. Letournel's study of 492 patients with posterior column fractures showed 81.82 % favourable results for isolated fractures, which dropped to 29.4 % with concomitant posterior wall involvement.⁴ Similarly, Matta's study reported a 100 % 20-year survival rate for isolated posterior column fractures, reducing to 85 % when both fracture types were present.⁵

The objective of this study was to compare clinical and radiological outcomes following surgical fixation of posterior column acetabular fractures, with and without concomitant posterior wall involvement. We hypothesize that fracture patterns involving the posterior wall will result in worse functional outcomes, despite achieving anatomical reduction surgically.

2. Methodology

A prospective, comparative study was conducted in the department of orthopaedic surgery at tertiary care trauma centre, from July 2017 to July 2022. Inclusion criteria of the study was all skeletally mature patients (>18 years old) presenting to outpatient and emergency care setting with acute (<21 days old), elementary/associated posterior column acetabular fracture and managed surgically for the same. Indications for surgery were any (medial, anterior or posterior) roof arc angle of less than 45°, instability of hip joint, incarcerated soft tissue or bony fragment, more than 2 mm fracture displacement, and incongruous joint due to displacement of posterior column in associated both column fracture. All patients with pathological fracture, concomitant ipsilateral femur fracture, acetabular fractures not involving posterior column and posterior column fractures with secondary congruence were excluded from the study. Written, informed consent was taken from all patients prior to enrolling them into the study. Institutional Ethical Committee approval was taken prior to initiation of the study.

All the patients were clinically and radiologically assessed. Pre-operative radiological examination included radiographs of the affected hip (pelvis with bilateral hip joint-anteroposterior view and judet views of the involved side), along with Computed Tomographic (CT) scans with 3-D reconstructions to evaluate the fracture pattern. The medial, anterior & posterior roof arc angles were measured on AP, obturator oblique, and iliac oblique views respectively. Fractures were classified according to Judet & Letournal classification of the acetabular fractures.¹

Surgical approach: Open reduction was done through the standard Kocher Langenbeck approach in all patients. All patients were operated on fracture table (Technomed TMI 1206 Hanging Type Orthopaedic OT Table) in lateral position for approaching posterior column. For transverse fracture pattern, prone position was used to prevent the femoral head from moving medially. After palpating the greater trochanter on the outer aspect of thigh, a skin incision of approximately 20 cm, with the proximal limb curving towards the PSIS and halting 6 cm short of this bony point, and the distal limb of the incision continuing 15 cm along the lateral aspect of the femur, was given. The sciatic nerve was located over the quadratus femoris and was tracked proximally. After identifying the fracture, marginal impaction of posterior wall was elevated using femoral head as the template. If involved, the posterior wall was reduced using pelvic reduction forceps with pointed ball tips in the sciatic notch, and the reduction was maintained with forceps or a ball spike pusher until final fixation. For fixation of posterior column, a Schanz screw in the ischium was employed as a joystick for manipulating the free fragment, and in cases of transverse fractures, for lateralizing and derotating the distal fragment. In case of transverse fractures, distal fragment containing the quadrilateral plate was reduced by hook inserted through greater sciatic foramen. By putting a finger through the sciatic notch on the quadrilateral plate, reduction was examined for an evident gap or step-off. The reduction was then examined with an image intensifier. Fracture was fixed with lag screws and pre-contoured 3.5 mm reconstruction plates in buttress mode. Posterior wall fracture was fixed separately in Group B after achieving maximum anatomic reduction. To check for any clicks, the hip was rotated and flexed, and fluoroscopic examination was performed to rule out any intra-articular hardware/bony fragment. The piriformis and obturator internus were sutured to their original tendons as well as to the surrounding boundaries to reconstruct the muscle bed. After thorough irrigation, wound was closed in layers.

Follow-up: Ankle physiotherapy and static quadriceps drills were started at the earliest. Patients were followed at fixed interval of 2 weeks, 6 weeks, 2 months, 3 months & 6 monthly till the last follow up. Post-operative day 3 onwards, dynamic quadriceps range of motion exercises were started. Toe touch walk was permitted after 2 weeks. At the end of 2nd month, partial weight bearing was started and by the end of third month full weight bearing walk was allowed. Functional outcomes were calculated at each follow-up using Merle D'Aubingne & Postel criteria. For radiological assessment, Matta's reduction criteria was assessed during the immediate post-operative period. Matta's radiographic grading was done at final follow-up.

Statistical analysis: Statistics was performed using SPSS for Windows (Version 21.0, SPSS Inc., Chicago). Categorical variables were compared using chi-square test, with p-value <0.05 to be considered statistically significant and a 95 % confidence interval.

3. Results

A total of 56 patients with acetabular fractures met the inclusion criteria of the study. Patients were operated at a mean of 6.3 days (range 5–16 days) of sustaining injury. Out of 56 operated patients, only 52 patients (92.8 %) were available for regular follow-ups. One (1.78 %) patient died due to COVID-19, one patient (1.78 %) succumbed to her injuries sustained in a Road Traffic Accident (RTA) and two patients (3.56 %) were lost to follow-up after stitch removal. Twenty eight (53.8 %) patients in the study were males and 24 (46.2 %) were females. Forty eight (92.3 %) patients sustained injury due to RTA and 4 (7.7 %) patients sustained injury due to fall from height (FFH). The mean follow-up period was 14.4 months (range = 12–26 months). Patients were divided into 2 groups: posterior column fracture without posterior wall involvement (Group A) and posterior column fracture with posterior wall fracture (Group B).

There were 32 patients with acetabular fractures involving posterior column without posterior wall in Group A (Fig. 1, Fig. 2) with mean age of 36.5 years (range 18–58). In this group 5 patients had concomitant cardiovascular condition, 4 patients had diabetes mellitus, 1 patient had bronchial asthma and 1 patient had generalized anxiety disorder. There were 20 patients with acetabular fractures involving posterior column with posterior wall fractures in Group B (Fig. 3, Fig. 4) with mean age of 39 years (range 21–60). Types of fracture patterns seen in each group are summarized in Table 1. In this group 6 patients had concomitant cardiovascular condition and 3 patients had diabetes mellitus. The two groups were similar in terms of mean age and medical comorbidities of the patients.

Fig. 1.

A 40 year old male with injury to his right hip. a & b: Radiograph showing pelvis with bilateral hip (antero-posterior view) and right hip judet views (iliac oblique and obturator oblique) showing transverse fracture pattern right acetabulum without posterior wall involvement (Group A). c & d: Immediate post-operative radiograph (AP view and Judet views) after open reduction internal fixation with 10 hole reconstruction plate. e & f: Radiographs at final 2 year follow-up (AP and Judet views).

Fig. 2.

Clinical photographs showing healthy scar tissue with good range of motion of patient with transverse fracture pattern right acetabulum without posterior wall involvement (Group A) at final 2 year follow-up.

Fig. 3.

A 25 year old male with injury to his left hip. a & b: Radiograph showing pelvis with bilateral hip (antero-posterior view) and left hip judet views (iliac oblique and obturator oblique) showing transverse fracture pattern left acetabulum with posterior wall involvement (Group B). c & d: Immediate post-operative radiograph (AP view and Judet views) after open reduction internal fixation with 6 hole and 10 hole reconstruction plates. e & f: Radiographs at final 2 year follow-up (AP and Judet views).

Fig. 4.

Clinical photographs showing healthy scar tissue with good range of motion of patient with transverse fracture pattern left acetabulum with posterior wall involvement (Group B) at final 2 year follow-up.

Table 1.

Table showing types of fracture pattern in group A (acetabular fractures involving posterior column without posterior wall fracture) and group B (acetabular fractures involving both posterior column and posterior wall fractures).

Fracture Pattern	Group A	Group B
Transverse	20 (62.50 %)	0 (0 %)
T-type	6 (18.75 %)	0 (0 %)
Both Column	6 (18.75 %)	0 (0 %)
Posterior Wall + Posterior Column	0 (0 %)	10 (50 %)
Transverse + Posterior Wall	0 (0 %)	10 (50 %)
Total	32 (100 %)	20 (100 %)

Matta's radiographic criteria for immediate post-operative reduction: In Group A, there were 16 (50 %) patients with anatomical reduction, 12 (37.5 %) patients with imperfect reduction and 4 (12.5 %) patients with poor reduction. In Group B, there were 10 (50 %) patients had anatomical reduction, 8 (40 %) patients had imperfect reduction and 2 (10 %) patients had poor reduction. On comparison, the results were not found to be statistically significant (p = 0.957, Table 2).

Table 2.

Table showing comparison of immediate post-operative, Matta's Radiographic reduction criteria between group A and group B.

Post Op Reduction	Group A	Group B	p-value
Anatomical (<1 mm)	16 (50 %)	10 (50 %)	–
Imperfect (1 mm–3mm)	12 (37.5 %)	8 (40 %)	–
Poor (>3 mm)	4 (12.5 %)	2 (10 %)	–
Total	32 (100 %)	20 (100 %)	0.957

Matta's radiographic grading at 1 year follow-up: In Group A, at final 1 year follow-up, 15 patients (46.8 %) were graded excellent radiographically, 6 patients (18.75 %) were graded good, 10 patients (31.25 %) were fair and 1 (3.1 %) was graded as poor. In Group B, 9 patients (45 %) were graded excellent, 6 patients (40 %) good, 4 patients (20 %) fair and 1 (5 %) as poor. On comparison, the results were not found to be statistically different between the two groups (p = 0.7113, Table 3).

Table 3.

Table showing comparison of functional outcomes between group A and group B as per Merle D'Aubingne & Postel criteria at final 1 year follow-up.

Merle D'Aubingne & Postel Criteria	Group A	Group B	p-value
Excellent	18 (56.25 %)	8 (40 %)	–
Good	10 (31.25 %)	2 (10 %)	–
Fair	3 (9.4 %)	8 (40 %)	–
Poor	1 (3.1 %)	2 (10 %)	–
Total	32 (100 %)	20 (100 %)	0.02

Functional outcomes (Merle D'Aubingne & Postel criteria): In group A, at final 1 year follow-up, 14 patients (75 %) achieved excellent functional results, 10 patients (38.46 %) achieved good functional results, 7 patients (21.8 %) had fair outcome and 1 (3.1 %) had poor functional outcome. In group B, 8 patients (40 %) had excellent functional results, 2 patients (10 %) had good, 8 patients (40 %) had fair and 2 (10 %) had poor functional outcome. Group A was found to have significantly better functional outcomes compared to Group B (p = 0.02, Table 4).

Table 4.

Table showing comparison of Matta's Radiographic Grading between group A and group B at final 1 year follow-up.

Matta's Radiographic Grading	Group A	Group B	p-value
Excellent	15 (46.8 %)	9 (45 %)	–
Good	6 (18.75 %)	6 (30 %)	–
Fair	10 (31.25 %)	4 (20 %)	–
Poor	1 (3.2 %)	1 (5 %)	–
Total	32 (100 %)	20 (100 %)	0.7113

Complications: In group A, there were 2 cases of iatrogenic sciatic nerve palsy and 1 patient developed deep infection. There was no case of avascular necrosis, early post-traumatic secondary arthritis, heterotopic ossification or wound complications at 1 year follow-up. In group B, 2 patients (10 %) developed post-traumatic early arthritis at 1 year follow-up. One patient got re-operated and converted to total hip arthroplasty (THA) at 1.5 year post-operatively and the other, at 2 years post-operatively. Two patients had superficial infection which recovered after 8 days of intravenous antibiotic course with daily cleaning and dressing. There were no other complication seen in this group. There was no statistically significant difference seen in complication rates between the two groups (p = 0.9, Table 5).

Table 5.

Table showing comparison of complications between group A and group B during the 1 year follow-up period.

Complications	Group A	Group B	p-value
Post-traumatic early arthritis	0 (0 %)	2 (10 %)	–
Iatrogenic Sciatic Nerve Palsy	2 (6.25 %)	0 (0 %)	–
Deep Infection	1 (3.125 %)	0 (0 %)	–
Avascular Necrosis of femoral head	0 (0 %)	0 (0 %)	–
Heterotopic Ossification	0 (0 %)	0 (0 %)	–
Total	3 (9.375 %)	2 (10 %)	0.9

4. Discussion

Posterior column and posterior wall acetabular fractures present significant challenges in orthopaedic trauma, often leading to complications such as hip instability, early onset of post-traumatic arthritis, and chronic hip pain if anatomical reduction is not achieved. This study aimed to evaluate the clinical and radiological outcomes of surgical fixation for these fractures, specifically comparing posterior column fractures with and without posterior wall involvement. Our findings demonstrate that significantly better functional outcomes after surgical fixation in patients with isolated posterior column fractures, compared to those involving both the posterior column and posterior wall. This is consistent with the literature, where Letournel reported 81.82 % favourable outcomes for isolated posterior column fractures, which significantly dropped to 29.4 % when posterior wall involvement was present.⁴ Similarly, Matta's study indicated a 100 % 20-year survival rate for isolated posterior column fractures, reducing to 85 % with concurrent posterior wall fractures.⁵

A critical review of current studies, including those by Min et al. and others, suggests that while anatomical reduction of both the posterior column and posterior wall is achievable, the presence of a posterior wall fracture does not necessarily compromise functional outcomes if the treatment algorithm is meticulously followed.⁶ Min et al. found no significant differences in reduction accuracy, radiographic results, clinical outcomes, or complication rates between patients with and without posterior wall involvement when a standardized surgical protocol was applied.⁶ Similarly, studies by Shin et al. and Min et al. showed that in associated both column acetabular fractures with or without posterior wall involvement, posterior wall fragment fixation can be successfully ignored if attached to acetabulum and contributing to hip joint congruency. It did not result in any difference in clinical outcome between the two groups.^6,7

However, literature has shown that when posterior wall is concomitantly involved with another elementary/associated acetabular fracture, the morphology of posterior wall fragment is significantly different, and often involves the roof of acetabulum. Hence, these concomitant posterior wall fractures are not morphologically similar to isolated posterior wall acetabular fractures.⁸ A study by Magu et al. emphasized the necessity of precise reduction and stable internal fixation of posterior wall fragment to improve long-term outcomes and reduce the risk of post-traumatic arthritis in patients with acetabular fractures involving posterior wall.⁹ These studies emphasize on the importance of anatomical reduction in acetabular fractures with posterior wall involvement, to achieve comparable functional outcomes. The results of our study demonstrate inferior functional outcomes despite anatomical reduction and surgical fixation in posterior column acetabular fractures without separate fixation of posterior wall.

The complexity of these injuries necessitates a nuanced approach. Factors such as the size and displacement of the posterior wall fragment, patient-specific anatomical considerations, and the surgeon's expertise play pivotal is in determining outcomes. The choice of surgical approach—whether using the ilioinguinal or the extended Kocher-Langenbeck approach—must be tailored to achieve optimal fracture reduction and fixation. The conventional strategy to fix both columns, using anterior with posterior approach, has been considered extensive and aggressive by most surgeons. These are associated with significant intra- and post-operative complications including life threatening haemorrhage. Recent studies have evaluated role of single posterior approach for treatment of combined, transverse-posterior wall acetabular fractures.^{10, 11, 12, 13, 14}

The complication rate in our study, including nerve injuries and post-traumatic arthritis, aligns with those reported for the ilioinguinal approach, underscoring the necessity for precise surgical techniques and comprehensive postoperative management to mitigate these risks. The observed development of post-traumatic arthritis highlights the need for ongoing surveillance and potential early interventions to preserve joint function. Notably, iatrogenic sciatic nerve palsy occurred in two patients (6.25 %), which is higher than in other studies. According to Tornetta et al. and Helfet et al., the peroneal division of the sciatic nerve is at risk during fractures treated with a posterior approach, even with an expert surgeon damaging the nerve in 2 % of cases.^15,16 Multiple causes for sciatic nerve injury have been identified including direct trauma during screw and plate insertion, improper hip and knee positioning, and the use of retractors and clamps. Positioning the Hohman retractor in the lesser sciatic notch can help avoid nerve damage. Additionally, one patient (1.9 %) developed a deep infection, treated successfully with intravenous antibiotics and sequential debridement. Our study demonstrated lower infection rates than literature. Infection rates in other studies range from 2.7 % to 22.7 %.^17,18 This could be attributed to strict aseptic protocols, careful soft tissue handling, and judicious antibiotic use at our centre.

The study has several limitations. Firstly, the sample size is relatively small, which may affect the generalizability of the findings. Future research should involve larger, multi-cantered, randomized studies to better assess the reproducibility of our results. Secondly, the follow-up period in this study was relatively short. While this duration is sufficient for observing early failures, it may not capture long-term complications such as avascular necrosis of the femoral head and post-traumatic arthritis, which can develop 3–4 years post-injury. Thirdly, there was inconsistent adherence to the at-home rehabilitation protocol among patients. We believe that the rehabilitation of complex fractures, especially those involving the acetabulum, benefit significantly from a structured and supervised rehabilitation program conducted by trained professionals.

5. Conclusion

Posterior column acetabular fractures involving the posterior wall have worse functional outcomes and are associated with early failure and post-traumatic arthritis, when treated with isolated posterior column fixation. Future studies should evaluate morphology of posterior wall fragment in the complex fracture patterns, role of its additional surgical fixation and compare it to those with isolated posterior wall fractures.

CRediT authorship contribution statement

Abdul Qayyum Khan: Conceptualization, Methodology, Validation, Formal analysis, Investigation, Resources, Data curation, Writing – original draft, Supervision, Project administration. Divas Gupta: Conceptualization, Methodology, Validation, Formal analysis, Investigation, Resources, Data curation, Writing – original draft, Project administration. Madhav Chowdhry: Methodology, Validation, Software, Formal analysis, Investigation, Data curation, Writing – original draft, Writing – reviewing and editing. Mohammad Baqar Abbas: Methodology, Validation, Formal analysis, Investigation, Resources, Data curation, Writing – original draft, Writing – Reviewing and Editing, Supervision, Project administration. Julfiqar: Methodology, Validation, Investigation, Resources, Supervision, Writing – Reviewing and Editing.

Patient consent

Written, informed consent was obtained from every patient prior to enrolment in the study.

Consent statement

Written informed consent was received from every patient before enrolling the patient in the study and for publication of the patient's information for research purposes.

Ethical clearance

Institutional ethical committee approval was taken before proceeding with study. Ethical committee approval document is attached and the reference number is IECJNMC/377.

Authors statement

All authors have contributed significantly to the research and manuscript. Authors do not have any conflict of interests to disclose. Contribution from each author have been mentioned separately in the Credit Author statement.

Ethics statement

Institutional ethical committee approval was taken before proceeding with study.

Institutional Ethics Committee, Jawaharlal Nehru Medical College & Hospital, Faculty of Medicine, Aligarh Muslim University approved the study with reference number is IECJNMC/377 held on 07/08/2021.

Funding statement

This study has not received any funding from any source.

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.