Acetabular fractures are complex fractures, caused mainly by high-velocity trauma. There are various fracture patterns, depending on the position of the hip during the impact, and the prognosis can vary in different subtypes after surgical treatment. Cartilage damage in these types of fractures can lead to future development of disabling osteoarthritis¹⁾. Arthritis occurs in approximately 12% to 57% of patients after acetabular fractures²⁾.

However, open reduction and internal fixation (ORIF) may be required for most acetabular fractures, except indications like stable and concentrically reduced fractures, fractures where the superior acetabular dome is not involved, fractures where a large part of the acetabulum is found to be intact etc. Depending on the roof arc measurement, those greater than 45° on anteroposterior, obturator and iliac oblique views, those fractures with both columns with secondary congruence, low T shaped fractures, low transverse and low anterior column fractures¹⁾ are the other indications where ORIF may not be required. Although ORIF has been regarded as the gold standard treatment, the surgery is difficult because of the anatomical location and the structural complexity²⁾. Good functional results have been reported after surgical treatment of isolated acetabular fractures. However, six months is required for restoring optimal hip function³⁾.

With the high incidence of arthritis post-acetabular fractures, total hip replacement (THR) has historically been a reserved option and a paradigm shift has occurred where acute total hip arthroplasty may be indicated in a certain subset of patients. In addition, there is less evidence with regard to performing THR for treatment of a fractured acetabulum²⁾.

Henry et al.⁴⁾ concluded that the prevalence of ORIF was 25 times higher than that of hip arthroplasty compared with matched controls among patients with fractures of the acetabulum. This finding was mainly associated with women, older patients, etc.

Bias has been observed in operative treatment of complex fractures, non-operative treatment of anterior column fractures and non-operative treatment in severely comorbid patients⁵⁾. Due to the lack of adequate knowledge regarding the prognosis of THR followed by ORIF and non-operative treatment of acetabular fractures, there is a need to conduct additional studies. Thus, the current study was conducted in order to perform an assessment and comparison of the functional outcomes of study subjects in the ORIF and non-ORIF groups during the follow-up period compared to baseline.

This longitudinal comparative study, which included 40 adult patients aged older than 18 years and admitted for THR for either post-traumatic arthritis after an acetabular fracture or for primary management of a fracture in M S Ramaiah Medical College and Hospital, urban Bengaluru, who were willing to participate in the study, was conducted after obtaining ethical clearance from the Ethics Committee of M S Ramaiah Medical College and Hospital (No. ECR/215/Inst/Ker/2021). The written informed consent was waived by the institutional ethical committee due to the retrospective nature of the study. The study was conducted from April 2012 to March 2017. Selection of all 40 patients was based on purposive sampling. Patients with history or findings of active sepsis, malignancies, neurovascular injuries in the ipsilateral limb, other surgeries performed on the ipsilateral limb, and cognitive dysfunction were excluded. Twenty-four patients had undergone ORIF, and 16 patients had undergone non-operative management for acetabular fractures. All patients underwent clinical and radiological evaluation and relevant lab examinations were performed. Acetabular bony defects were classified according to Paprosky classification⁶⁾. The surgeries were performed by a single surgeon with substantial experience in performance of total hip arthroplasty using a ‘posterior approach’. Placement of an uncemented acetabular cup was planned in all patients. Adjuncts including use of a large hook around the neck to pull the neck anteriorly instead of pointed Hohmann levering on the anterior column, in-situ osteotomy of the neck, trochanteric osteotomy, and obstructing implant removal of previous implants were used during performance of the surgical technique using the posterior approach. The following interventions were applied based on the specific fractures and defects of the acetabulum (Table 1).

Table 1 . Initial Fracture Involvement and the Treatment Options Considered.

Fracture involvement	Treatment option
1. Posterior wall mid portion up to but not involving groove of ischium	Neutral placement of acetabulum shell with 20° elevated liner
2. Superior wall and part of posterior wall	High hip center and medialization of cup
3. Superior and posterior wall	Structural graft +/– posterior augment column buttress/shim augment
4. Quadrilateral plate fracture, +/– medial defect Protrusion of acetabulum Anterior column/wall	Cage Medialization of center of femoral head Posterior plating + impaction grafting Large hemispherical cup Cup – cage Combination of above

After obtaining written informed consent, the data were collected using a semi-structured questionnaire that consisted of demographic details, history of injury, and details on clinical and radiological evaluation of the hip including the Harris hip score (HHS).

The HHS is a physician elicited scale for measuring the functional status of an individual with hip pathologies. It is a validated tool for assessment of functional status, including the domains on pain, mobility and walking, joint movement, and absence of deformity before and after a surgical procedure^7-9).

Following THR, the patients were followed up for monitoring of functional outcomes for the HHS and comparison between the ORIF and non-ORIF groups was performed. The patients were followed up until the last patient had completed at least three years of follow-up. The HHS at the end of one year and at the end of the mean follow-up period was also recorded. They were also followed-up for complications including deformity of a lower limb, Trendelenburg gait¹⁰⁾ or lurching gait, cup loosening and severe stiffness of the hip joint, superficial wound infection, and Heterotrophic ossification (HO) (Fig. 1-4).

Figure 1. (A) Central fracture dislocation conservatively managed elsewhere. (B) Developed secondary osteoarthritis with protrusio acetabuli. (C) Three-dimensional reconstructed computed tomography image showing medial wall deficit. (D) Postoperative X-ray impaction bone grafting with femoral head and cementless total hip replacement. (E) Eight-year follow-up X-ray.

Figure 2. (A) Acetabular fracture-posterior wall+posterior column with inferior pubic rami fracture. (B) Surgically managed trochanteric osteotomy with posterior wall and column fixation. (C, D) Follow-up X-ray of 3 months patient developed postero-superior defect with secondary osteoarthritis. (E) Postoperative X-ray cementless total hip arthroplasty with posterior column buttress augment. (F) Follow-up X-ray of 9 months developed extensive heterotopic ossification.

Figure 3. (A) X-ray pelvis showing posterior wall communited fracture with posterior column with inferior rami fracture. (B, C) Three-dimensional reconstruction computed tomography showing posterior wall communited fracture with posterior column with inferior rami fracture. (D) Postoperative X-ray orif with plating. (E) Follow-up X-ray of 3 months. (F) X-ray postoperative 2 year follow-up patient secondary osteoarthritis with concentric joint space reduction, acetabular contour maintained. (G, H) Postoperative cementless total hip replacement.

Figure 4. (A, B) Computed tomography (CT) images showing posterior wall communited fracture with posterior column fracture with marginal impaction. (C) X-ray showing posterior wall communited fracture with posterior column fracture with posterior dislocation. (D, E) three-dimensional reconstruction of CT showing posterior wall communited faractue with posterior column fracture with posterior dislocation and postero-superior defect in the acetabulum. (F, G) Follow-up X-ray after 6 months secondary osteoarthritis post orif. (H, I) Three-year follow-up X-ray spring plate removal with retaining recon plate and cementless total hip replacement medialization and proximalisation of acetabulum component with smaller acetabular component. Center of femoral head higher than normal side due to postero superior defect.

All data were entered into Microsoft Excel 2013 (Microsoft). The parametric continuous data were expressed in means and standard deviation and non-parametric in medians and range, and the categorical data were expressed in proportions. The comparison of the HHS within the groups from the baseline to the first year and at the end of the mean follow-up period was performed using repeated measures ANOVA and the comparison of HHS between groups was performed using the independent t-test. The analysis was performed using IBM SPSS Statistics for Windows (ver. 20.0; IBM Corp.). A P-value of less than 0.05 was considered statistically significant.

The mean age of the study participants was 37.95± 12.58 years, ranging from a minimum of 19 years to 70 years. No significant difference in the mean age distribution, sex distribution, and preoperative or baseline HHS was observed between the ORIF and non-ORIF groups (P>0.05). The mean follow-up period was 62.79±12.60 months and 65.06±15.38 months in the ORIF and non-ORIF groups respectively. The median follow-up period was 4.05 years and 5.00 years, ranging from 3 to 7 years and 3 to 7.1 years in the ORIF and non-ORIF groups respectively. Sixteen patients (57.1%) in the ORIF group had simple fractures and six patients (60.0%) had associated combined fractures, while 12 patients (42.9%) in the non-ORIF group had simple fractures and four patients (40.0%) had associated combined fractures. Regarding simple fractures, most patients in the ORIF group had a posterior column fracture (100%) and medial wall fractures were the most common in the non-ORIF group (100%) (Table 2).

Table 2 . Socio-demographic and Clinical Profile of the Patients.

Variable	ORIF (n=22)	Non-ORIF (n=16)
Age (yr)*	38.41±12.88	37.31±12.54
Time since injury (yr)	4 (0.4-10)†	3.5 (0.006-18)†
Sex*
Male	17/30 (56.7)	13/30 (43.3)
Female	5/8 (62.5)	3/8 (37.5)
Preoperative HHS*	57.55±7.35	52.25±9.02
Mean follow-up (mo)	62.79±12.60	65.06±15.38
Type of acetabular fractures
Simple fractures
PW	10/19 (52.6)	9/19 (47.4)
PC	6/6 (100)	0/6 (0)
MW	0/3 (0)	3/3 (100)
Associated fractures
PW+PC	1/2 (50.0)	1/2 (50.0)
PC+MW	0/1 (0)	1/1 (100)
PC+SW+MW	1/1 (100)	0/1 (0)
PC+AC	1/1 (100)	0/1 (0)
PW+MW+Pipkin fracture	0/1 (0)	1/1 (100)
AC+MW	1/1 (100)	0/1 (0)
AC+AW+PW	0/1 (0)	1/1 (100)
PC+AC+MW	1/1 (100)	0/1 (0)
Bicolumn fracture	1/1 (100)	0/1 (0)

Values are presented as mean±standard deviation, median (range), or number (%)..

ORIF: open reduction and internal fixation, HHS: Harris hip score, PW: posterior wall fracture, PC: posterior column fracture, MW: medial wall with or without quadrilateral plate fractures, SW: superior wall, AC: anterior column, AW: anterior wall..

*P>0.05 (not significant) on applying test of significance..

^†0.4 years≈5 months; 0.006 years≈2 days..

Despite significant improvement in the mean HHS in each group in the postoperative period and at the end of the mean follow-up period compared to baseline (P<0.05), no significant difference in scores was observed between the ORIF and non-ORIF groups (P>0.05). The mean abduction angle, cup diameter, and degree of anteversion were also similar in both groups (P>0.05). A postoperative limp was also observed equally between the groups, although a severe limp was observed in patients in the ORIF group (100%). The majority of these patients in the ORIF group had an anteverted acetabular cup (64.3%) and 55.6% in the non-ORIF group. One patient in the non-ORIF group had a neutral acetabular cup and a retroverted cup (Table 3, 4).

Table 3 . Distribution of Outcomes of THA in ORIF and Non-ORIF Groups.

Outcome	ORIF (n=22)	Non-ORIF (n=16)
HHS
Postoperative	88.32±6.21	85.69±5.52
At the end of the mean follow-up	91.09±6.71	85.88±11.64
Abduction angle (°)	46.95±2.06	46.44±3.76
Cup diameter (mm)	50.00±3.02	50.56±3.83
Mean anteversion in degree (n=28)	13.61±7.18	11.30±3.53
Postoperative limp
No limp	18/29 (62.1)	11/29 (37.9)
+	1/3 (33.3)	2/3 (66.7)
++	1/3 (33.3)	2/3 (66.7)
+++	1/1 (100)	0/1 (0)
Position of the cup
Anteversion	18/28 (64.3)	10/28 (35.7)
Neutral	4/9 (44.4)	5/9 (55.6)
Retroversion	0/1 (0)	1/1 (100)
Heterotopic ossification (HO)
No HO	19/35 (54.3)	16/35 (45.7)
Grade 1	1/1 (100)	0/1 (0)
Grade 2	1/1 (100)	0/1 (0)
Grade 3	1/1 (100)	0/1 (0)
Limb length discrepancy
Yes	1/3 (33.3)	2/3 (66.7)
No	21/35 (60.0)	14/35 (40.0)
DeLee Charnley zones
No zones	19/33 (57.6)	14/33 (42.4)
1 zone	1/3 (33.3)	2/3 (66.7)
2 zones	2/2 (100)	0/2 (0)
Complications
Yes	3/5 (60.0)	2/5 (40.0)
No	19/33 (57.6)	14/33 (42.4)
Intervention required
Yes	1/3 (33.3)	2/3 (66.7)
No	14/35 (60.0)	21/35 (40.0)

Values are presented as mean±standard deviation or number (%)..

THA: total hip arthroplasty, ORIF: open reduction and internal fixation, HHS: Harris hip score..

Table 4 . Comparison of Mean HHS within the Groups Compared to Baseline.

Group	Baseline	Postoperative at 1 year follow-up	Postoperative at the end of mean follow-up	F-value	P-value
ORIF (n=24)	56.99±7.26	89.04±6.28	91.61±6.64	836.48	<0.05*
Non-ORIF (n=16)	52.10±8.97	85.69±5.55	85.74±11.56	140.17	<0.05*

Values are presented as mean±standard deviation..

HHS: Harris hip score, ORIF: open reduction and internal fixation..

*P<0.05..

After surgery, three hips (13.6%) in the ORIF group showed HO of Brooker class 1, 2, and 3 each. Leg length discrepancy was observed equally in both groups with no significant difference (P>0.05). Radiographic assessments of the acetabular components were performed in three zones as proposed by DeLee and Charnley; loosening of the prothesis was detected in two zones in two of these patients and loosening was detected in one zone in one patient in the ORIF group. However, in the non-ORIF group, loosening of the prosthesis was detected in one zone in two patients. Loose shell, stiff hip, massive bleeding, bone defect after plate removal, and high hip center were the complications observed in the ORIF group and trochanteric fracture and high hip center were observed in the non-ORIF group. There was no significant difference in the occurrence of complications (P>0.05). Head autograft and column buttress with medial augment were the interventions used in the non-ORIF group and re-revision of surgery, i.e., ORIF+augment+cemented cup was required in the ORIF group (Table 4, 5).

Table 5 . Comparison and Association of Various Outcome Variables of THA in ORIF and Non-ORIF Groups.

Outcome variable	ORIF (n=22)	Non-ORIF (n=16)	t-value (95% CI)	P-value
HHS
Postoperative	88.32±6.21	85.88±11.64	–1.35 (–6.58 to 1.32)	0.19
At the end of the mean follow-up	91.09±6.71	85.69±5.52	–1.75 (–11.28 to 0.84)	0.09
Abduction angle (°)	46.95±2.06	46.44±3.76	–0.54 (–2.44 to 1.41)	0.59
Cup diameter (mm)	50.00±3.02	50.56±3.83	0.51 (–1.69 to 2.82)	0.62
Mean anteversion in degree (n=28)	13.61±7.18	11.30±3.53	–0.95 (–7.31 to 2.69)	0.35
Postoperative limp*
Yes	4/8 (50.0)	4/8 (50.0)	-	0.69
No	18/30 (60.0)	12/30 (40.0)
Heterotopic ossification*
Yes	3/3 (100)	0/3 (0)	-	0.25
No	19/35 (54.3)	16/35 (45.7)
Limb length discrepancy*
Yes	1/3 (33.3)	2/3 (66.7)	-	0.56
No	21/35 (60.0)	14/35 (40.0)
DeLee Charnley zones*
Yes	3/5 (60.0)	2/5 (40.0)	-	>0.99
No	19/33 (57.6)	14/33 (42.4)
Complications*
Yes	3/5 (60.0)	2/5 (40.0)	-	>0.99
No	19/33 (57.6)	14/33 (42.4)
Intervention required*
Yes	1/3 (33.3)	2/3 (66.7)	-	0.56
No	14/35 (60.0)	21/35 (40.0)

Values are presented as mean±standard deviation or number (%)..

THA: total hip arthroplasty, ORIF: open reduction and internal fixation, CI: confidence interval, HHS: Harris hip score..

*Fisher’s exact test applied..

No such detailed preoperative planning and performance of THR based on a primary fracture pattern has been reported in the literature. Several articles have reported on acetabular defects for revision THR.

The complexity of the procedure is dependent on the fracture pattern and the initial management of the fracture¹¹⁾.

Pseudoarthrosis or non-union after grossly displaced fractures has been observed in the non-ORIF group seen in magnetic resonance imaging as non-union/fibrous union. In a clinical scenario gross movement will not occur at the site of non-union. Thorough curettage and reaming with impaction of bone at the site of non-union will eventually be helpful in integration of an uncemented shell.

Depending on the situation, usage of the femoral head as a structural graft, impaction bone grafting, or column buttress augment is required. Bulk autograft bone from the femoral head is mainly used in cases of protrusion or when there are columnar defects¹²⁾.

Posterior plating should be reserved for cases of pelvic discontinuity and/or supplemental grafts¹³⁾.

Results showing good long-term survival have been reported for acetabular bone impaction grafting, a biological technique used in reconstruction of bone stock loss¹⁴⁾. However, these types of cases can usually be managed with primary implantation of the shell alone.

Previously, cemented components were used frequently; however, there were problems such as distorted acetabular anatomy, young age, early cementing techniques, and poor interdigitation of cement in sclerotic bone¹⁵⁾. A high rate of component loosening was observed in these patients¹⁶⁾.

van den Broek et al.¹⁷⁾, who recently described the use of a dual mobility cup cemented into a porous multihole cup with locking screws, concluded that it can be regarded as a safe option for treatment of acetabular fractures in elderly patients with encouraging functional and radiological outcomes. However, their study included acute fractures of the acetabulum and not arthritic hips following old acetabular fractures.

Lizaur-Utrilla et al.¹⁸⁾ compared the long-term results from use of cementless acetabular components in THR with previous acetabular fractures to those with non-traumatic THR. No significant difference with regard to postoperative follow-up, acetabular survival, and reoperations was observed between the two cohorts, while significant differences were observed for postoperative HHS. Thus, they concluded that cementless THR in previous cases of acetabular fracture is a suitable option.

Ranawat et al.¹⁹⁾ conducted a study of 32 cases of post-traumatic arthritis after an acetabular fracture in patients who underwent THR. They found no significant difference in postoperative HHS between the ORIF and non-ORIF groups, similar to our study. Of their 32 cases, five cases showed periacetabular radiolucencies (two each in one and three DeLee and Charnley zones and one in two DeLee Charnley zones), as compared to five (three in a single DeLee Charnley zone and two in two DeLee Charnley zones) out of our 40 cases. The Kaplan–Meier 5-year survivorship score was 79% and 97%, and the end points were revision arthroplasty and aseptic acetabular loosening, respectively, while ours was 100% in both scenarios. In their study, development of HO occurred in 46% of ORIF cases and 38% of non-ORIF cases, compared to 13.5% and 0% of our ORIF and non-ORIF cases, respectively. However, neither showed statistical significance.

Zhang et al.²⁰⁾, who conducted a 5-year follow-up study on 55 joints, including 32 in the ORIF group and 23 in the non-ORIF group, reported that excellent results were obtained from THR with both cemented and uncemented components in failed treatment of acetabular fracture. Their study included one case of leg-length discrepancy, compared to three in our study. The Kaplan–Meier 5-year survivorship score was the same as that of our study, i.e., 100%.

Huo et al.²¹⁾ conducted a study that included 21 hips that had undergone exclusive cementless THR surgeries.

Thirty-four post acetabular fracture arthritic hips with uncemented acetabular components were studied for a period of at least 10 years by Berry and Halasy²²⁾. The authors concluded that the rate of loosening was low in these patients; however, osteolysis and polyethylene wear were an area of concern.

A study by Lee et al.²³⁾ reported satisfactory results and excellent survival for ceramic-on-ceramic bearing in total hip arthroplasty at a minimum follow-up of five years without detectable wear, osteolysis, prosthetic joint infection, or prosthetic loosening. However, unlike in our series, ORIF and non-ORIF groups were not studied separately.

Bellabarba et al.²⁴⁾ reported on 30 cementless acetabular reconstructions after acetabular fractures with an mean follow-up period of 63 months. Twenty-seven patients had a good or excellent HHS.

Types of fractures and corresponding technical aspects of surgery have not been previously discussed in the literature.

After thorough analysis of the literature, we found that this study is the only one of its kind. No study regarding this perspective of approaching arthritis of the hip post-acetabular fracture has yet been published. The reader will attain a clear understanding of how such patients can be managed in a more methodological way, and therein lies the strength of this article. In addition, we have included a wider variety of cases, all of whom underwent surgery performed by the same surgeon at the same center.

Limitations of our study include its retrospective nature with a mean duration of follow-up, which is relatively long-term. There were fewer cases involving a grossly displaced bicolumn fracture and a severely deformed pelvis.

THR resulted in improved functional outcome during the follow-up period and better ORIF was achieved in terms of functional outcome, and re-intervention was not required for any of the posterior fractures at the end of the mean follow-up period. It can also be helpful in deciding on placement of the acetabular component with respect to the primary fracture pattern, thus leading to improved outcome and, eventually, patient functionality.

No funding to declare.

No potential conflict of interest relevant to this article was reported.