Quadrilatral plate stabilization: Conventional reconstruction plate or anatomical plate: A systematic review and meta-analysis

Abstract

Background

Quadrilateral plate fractures are a persistent challenge to orthopedic surgeons. The last decade has seen the development of novel anatomical plates for fixation of these fractures but they haven't been widely adopted. The aim of this study was to study the literature published on plate fixation of quadrilateral plate fractures and analyse the differences between the time-tested reconstruction plate and anatomical plate.

Methods

PRIMSA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed and the search was performed on 3 databases – PubMed, SCOPUS, and EMBASE. The study was registered with PROSPERO (International Prospective Register of Systematic Reviews) under the registration number CRD420251017775. 12 studies of which 4 were comparative were chosen after thorough screening and a meta-analysis was performed between reconstruction plates and anatomical plates to study the intra-operative and post-operative results. The studies were conducted between 2007 and 2021.

Results

583 patients with an average age of 55.45 years of which 75.8 % were males were studied. Intraoperatively, surgical time and blood loss were found to be significantly less in the anatomical plate group versus the reconstruction plate group. Quality of reduction as per Matta's criteria and long term outcomes reported as per Merle's score were found to be similar in both the groups. The rate of complications was higher in the reconstruction plate group.

Conclusion

The anatomical plate is better for fixation of quadrilateral plate fractures in terms of intraoperative blood loss and operative time. However, the long term outcomes are equivocal.

Graphical abstract

1. Introduction

Treatment of acetabulum fractures has been notoriously evasive of consensus amongst orthopedic surgeons. With the changing population demographic, rising age and increasing incidence of high velocity road traffic accidents, acetabulum fractures are following suit. Quadrilateral plate is a vital part of the acetabulum, preventing medial displacement of the femoral head and has a high risk of fracture in osteoporotic patients.¹ These fractures, though not separately classified, are seen in many cases of acetabulum fractures whose patterns have been elaborated upon by Letournel et al.; most commonly the both column fracture, anterior column, anterior column posterior hemi-transverse, and T-shaped fractures.^2,3 Chang et al.,⁴ via his biomechanical cadaveric study, recognized that the anatomical reduction of the quadrilateral plate surface intraoperatively had a vital role in determining the outcomes of acetabular fractures. They also noted it to be the most common anatomical region for implant failure.

The optimum management of quadrilateral plate fractures, is to attain an anatomical reduction, control and correct the associated femoral head medial displacement and fixation ensuring adequate stability. However, probably due to the lack of a uniform classification system, treatment protocols for quadrilateral plate fractures have been elusive.⁵

Various options are available for surgical fixation of the quadrilateral plate. These include the classically described reconstruction plates, column lag screws, braided cables, heavy wires, percutaneous screw fixation [referred to by some as ‘magic Screw’] or buttress screw fixation.^{6, 7, 8} The mostly commonly used implant, the reconstruction plate, can be placed either suprapectineal or infrapectineal. The last decade has seen the evolution of anatomical plates for fixation of these fractures. These anatomical plates are side specific and are reported to have certain advantages.⁶

The shape of the pelvis is irregular and requires the reconstruction plate to be contoured and molded. This requires precision and is time consuming. Multiple attempts at molding the plate weakens the plate and increases the risk of implant failure. The molded plate in many cases cannot be attached to the pelvic surface in its entirety. This can lead to the reduced fragments being secondarily displaced when fixed with screws.

Multiple modifications to acetabular plates have been developed over time to combat these issues. Zha et al.⁹ developed an anatomical plate which fit over the quadrilateral surface and resisting its medial displacement, introducing the concept of quadrilateral resistance. Kistler et al.⁷ came forth with a novel fixation method, which buttressed the fracture and resisting the medial displacement of quadrilateral plate fracture. Karim et al.⁶ designed a new fixation technique to fix and resist the quadrilateral plate displacement. Schäffler et al.¹⁰ developed an acetabular anatomical wing plate for better purchase superiorly in osteoporotic fractures. Sen et al.¹¹ developed the anatomical quadrilateral plate to complement the exact anatomical shape of the brim from the superomedial surface. Primarily meant for osteoporotic patients, it can also be used for communited fractures in younger individuals.

Theoretically, anatomical plates do not require much molding and therefore take lesser operative time than conventional plates. They also retain their biomechanical strength. These benefits have been mentioned in a few studies scattered across literature, but no consensus has been achieved.^{1,12, 13, 14}

Through this review we wished to examine the available literature on the surgical management of quadrilateral plate fractures and to compare the intraoperative and postoperative results of the varying plate options.

2. Methodology

2.1. Search methodology

This review was conducted following the PRIMSA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, and the search was conducted on three databases – PubMed, EMBASE and SCOPUS.¹⁵ The study was registered with PROSPERO (International Prospective Register of Systematic Reviews) under the registration number CRD420251017775. The keywords used for the search were “[Quadrilateral] AND [Acetabulum]”. The total number of hits on the primary search was 200. The references of the shortlisted studies were also searched as part of a secondary search for any studies which could have been possibly missed.

2.2. Inclusion & exclusion criteria

Only articles which were in English were included in the review. Individual case reports, cadaver based studies, biomechanical studies, abstracts for conferences and study protocols were excluded. Amongst them, studies in which quadrilateral plate fixation was performed using buttress plates and outcomes were reported, both intra-operative and post-operative, were identified and shortlisted. The choice of surgical approach to fixation [ilioinguinal vs Stoppa's vs rectus split] had no bearing on inclusion in our review. Studies which did not report outcomes and studies which used other means of fixation such as cerclage wires, column lag screws and hook plates were excluded. All studies which appeared in duplication were eliminated.

2.3. Data collection and analysis

Two authors [AG and PB] did a thorough screening of all the articles found in the database searches. Any conflicts of opinion between the reviewers were mutually resolved after taking in inputs from the other co-authors and final consensus was reached. After this exclusion was done on the basis of study design. From the remaining studies, the tittles and abstracts were assessed for pertinence to this review. Full texts were read, and the articles deemed suitable were included for review and analysis [Fig. 1].

Fig. 1.

Literature search strategy.

Tables were constructed for evaluation of data. Table I mentions the study characteristics: the study groups, sample sizes, the type of plate used and outcomes evaluated. Table II is a summary of all the outcomes reported including intraoperative parameters, complications, Matta's reduction criteria¹⁶ and the long term outcomes such as Merle D'Aubigne and Postel score.¹⁷

Table 1.

Summary of included studies (2018–2023).

S no	Study	Year/Place	Type of study	Sample Size	Plate used	Outcomes measured
1.	Fan et al. 22 (2023)	2016–2021/China	Retrospective	178	Anatomical plate	Matta reduction criteria Merle Score Operative time Blood loss
2.	Wan et al. 18 (2022)	2015–2019/China	Retrospective	23	Anatomical plate	Matta reduction criteria Merle Score Operative time Blood loss
3.	Kwak et al. 13 (2022)	2018–2020/South Korea	Retrospective	39: 16 23	Anatomical plate Reconstruction plate	Matta reduction criteria Merle Score Operative time Blood loss
4.	Nicol et al. 1 (2020)	2007–2019/Canada	Retrospective	30: 10 20	Anatomical plate Reconstruction plate	Matta reduction criteria Operative time Length of stay Conversion to THA
5.	Wu et al. 12 (2020)	2016–2018/China	Retrospective	44: 22 22	Anatomical plate Reconstruction plate	Matta reduction criteria Merle Score Operative time Blood loss Length of stay
6.	Meena et al. 19 (2020)	2013–2018/India	Retrospective	90	Reconstruction plate	Matta reduction criteria Merle Score Operative time Blood loss
7.	Wang et al. 14 (2020)	2016–2017/China	Prospective	50: 15 35	Anatomical plate Reconstruction plate	Matta reduction criteria Operative time Blood loss
8.	Nadeem et al. 20 (2020)	2017–2018/Pakistan	Retsopective	21	Reconstruction plate	Matta reduction criteria Merle Score Operative time Blood loss
9.	Sen et al. 11 (2020)	2017–2020/India	Retrospective	33	Anatomical plate	Matta reduction criteria Pt reported outcomes
10.	Zha et al. 21 (2019)	2011/2015/China	Retrospective	24	Anatomical plate	Matta reduction criteria Merle Score Operative time Blood loss
11.	Tosounidis et al. 23 (2015)	2003–2011/UK	Retrospective	30	Reconstruction plate	Matta reduction criteria Merle Score
12.	Laflamme et al. 2 (2011)	4 yr/Canada	Retrospective	21	Reconstruction plate	Matta reduction criteria Merle Score Operative time Blood loss

Table 2.

Summary of demographics, operative time, blood loss, length of stay, quality of reduction, clinical outcomes, complications, and miscellaneous findings reported.

S no	Study	Group	Follow up	Age	M/F	Operative time	Blood Loss	Length of stay	Matta reduction	Merle Score/Patient reported outcome	Complications	THA conversion
1.	Fan et al22	QSP (n = 178)	Minimum 1 yr (1–5 yr)	57.8 ± 16.7	138/40	75 ± 29	440 ± 153		Anatomic:131 Imperfect:31 Poor:16	Excellent:125 Good:26 Fair:27 Poor:0	13 DVT 4 Fat liquefaction 15 obturator N praxia 2 screw loosening 6 PTOA 2 ON Femoral head
2.	Wan et al18	QSP (n = 23)	Atleast 1 yr	69.8 ± 6.1	18/5	166.5 ± 43.5	500 (50)		Anatomic:14 Imperfect:4 Poor:4	Excellent:13 Good:7 Fair:3 Poor:0	LCFN injury: 3 (13 %) Heterotopic Ossfication: 1 (4.3 %)
3.	Kwak et al13	QSP (n = 16)	Minimum 1 yr, Average 24.1 months	61.2 ± 12.8	14/2	109.9 ± 33.6	853.1 ± 329.3		Anatomic:14 Imperfect:1 Poor:1	Excellent:4 Good:9 Fair:3 Poor:0	0	2/16 conversion to THA
		Non QSP (n = 23)		53.5 ± 11.6	20/3	236.1 ± 97.9	1843.5 ± 752.5		Anatomic:21 Imperfect:2 Poor:0	Excellent:9 Good:13 Fair:1 Poor:0	1 lumbosacral plexopathy 2 PTOA	0
4.	Nicol et al1	QSP (n = 10)	1.9 ± 1.2	70 ± 9	6/4	222 ± 59		17 ± 8	Anatomic:3 Imperfect:6 Poor:1	OHS: 35 ± 10		0/9 conversion to THA
		Non QSP (n = 20)	5.6 ± 4.0	74 ± 8	14/6	261 ± 91		19 ± 11	Anatomic:1 Imperfect:7 Poor:12	OHS: 34 ± 11		3/8 conversion to THA
5.	Wu et al12	QSP (n = 22)	23.1 months	46.7 ± 11.6	18/4	245.1 ± 54.6	1136.4 ± 686.3	25.7 ± 6.3	Anatomic:16 Imperfect:5 Poor:1	Excellent:11 Good:9 Fair:1 Poor:1	4/23 (18.2 %) LCFN -1 Sciatic - 1 PTOA -2,	THA - 1
		Non QSP (n = 22)	26.1 months	50.8 ± 8.9	14/8	286.8 ± 59.3	1777.3 ± 944.6	26.8 ± 7.8	Anatomic:14 Imperfect:6 Poor:2	Excellent:9 Good:9 Fair:4 Poor:0	8/23 (36.4 %) DVT – 1, LCFN – 2 PTOA – 4, Infection −1	0
6.	Meena et al19	Non QSP (n = 41)	30.20	43.5 (18–82)	30/11	134.4 (90–200)	803.90 (400–1500)		Anatomic:15 Imperfect:17 Poor:9	Excellent + good:28 Fair + Poor:13	4 LCFN 1 Obturator N Palsy 1 DVT 1 SSI 4 Implant loosening
		Non QSP (n = 49)	23.31	45.02 (23–82)	43/6	107.14 (70–150)	491.84 (300–1200)		Anatomic:29 Imperfect:16 Poor:4	Excellent + good:37 Fair + Poor:12	4Obturator N Palsy 2 DVT 1 SSI 1 Implant loosening
7.	Wang et al14	QSP (n = 15)	Minimum 1 yr	46.6 ± 12.3	10/5	141.7 ± 52.9	880.0 ± 673.4		Anatomic:10 Imperfect:4 Poor:1		1 Screw loosening
		Non QSP (n = 35)		45.1 ± 12.6	22/13	170.7 ± 40.6	1177.1 ± 691.6		Anatomic:18 Imperfect:13 Poor:4		5/15: 1 DVT 1 Infection 1 PTOA 2 Obturator injuries
8.	Nadeem et al20	Non QSP (n = 21)	14.3 ± 2.1 months	40.67 ± 12.1	15/6	178 min			Anatomic:14 Imperfect:5 Poor:2	Excellent:10 Good:9 Fair:2 Poor:0	3 SSI
9.	Sen et al11	QSP (n = 33)	Minimum 1 yr	65.8 yr	28/5				Anatomic:28 Imperfect:5 Poor:0	Pt reported outcomes 100–22/33 90–7/33 80–3/33 70–1/33		1 conversion to THA
10.	Zha et al21	QSP (n = 24)		61.5 ± 9.2	15/9	110.3 ± 30.8 min	950.6 ± 348.6 ml		Anatomic:17 Imperfect:5 Poor:2	Excellent:15 Good:6 Fair:2 Poor:1	3 Heterotopic ossification 4 PTOA
11.	Tosounidis et al23	Non QSP (n = 30)		50.4	20/10				Anatomic: 11 Imperfect: 14 Poor:5	Excellent: 17 Good: 4 Fair: 6 Poor:3	2 LCFN 1 S1 deficit 3 HO 1 DVT	3 conversion to THA
12.	Laflamme et al2	Non QSP (n = 21)		64.3 ± 6.0	17/4	167 ± 41	1376 ± 608		Anatomic: 11 Imperfect:8 Poor:2	Excellent: 5 Good: 8 Fair: 1 Poor:0	1 obturator N praxia 3 Heterotopic ossification 4 PTOA	2 conversion to THA

2.4. Search and screening results

Out of the 200 studies obtained from the searches, 40 studies were selected for further screening. On the basis of the abstracts of these 40 papers, 12 studies were finally shortlisted. These 12 studies which were conducted between 2007 and 2021 were included in the systematic review.^{1,2,11, 12, 13, 14,18, 19, 20, 21, 22, 23}

2.5. Statistical analysis

OpenMeta Analyst and RevMan 5.1 software were used. Pooled estimates were calculated for intraoperative parameters such as mean blood loss and operative time, and post operative parameters like length of stay, complication rate, Matta's reduction criteria and outcomes on the basis of Merle's Score. Subgroup analysis was performed for all parameters by types of plate used. Additionally, data from comparative studies was extracted and a comparative analysis was done for parameters that were reported in at least 3 studies.

2.6. Risk of bias assessment

Risk of bias of the included studies was assessed using the methodological index for non-randomised studies [MINORS]²⁴ criteria. [Table III].

Table 3.

– Risk of bias summary based on MINORS criteria.

	Clearly stated aim	Inclusion of consecutive patients	Prospective collection of data	Endpoints appropriate to the aim of the study	Unbiased assessment of the study endpoint	Follow-up period appropriate to the aim of the study	Loss to follow up less than 5 %	Prospective calculation of the study size	An adequate control group	Contemporary groups	Baseline equivalence of groups	Adequate statistical analysis	Global score
Fan et al22	1	1	2	2	0	2	2	0	NA	NA	NA	NA	10
Wan et al18	2	2	2	2	0	2	2	0	NA	NA	NA	NA	12
Kwak et al13	2	2	2	2	0	2	1	0	2	2	2	2	19
Nicol et al1	2	2	2	2	0	2	2	0	2	1	2	2	19
Wu et al12	2	2	2	2	0	2	2	0	2	2	2	2	20
Meena et al19	1	2	2	2	0	2	2	0	NA	NA	NA	NA	11
Wang et al14	2	2	2	2	0	2	2	0	2	2	2	2	20
Nadeem et al20	2	2	2	2	0	2	2	0	NA	NA	NA	NA	14
Sen et al11	1	1	2	2	0	2	1	0	NA	NA	NA	NA	9
Zha et al21	2	1	2	2	0	2	2	0	NA	NA	NA	NA	11
Tosounidis et al23	2	1	2	2	0	2	2	0	NA	NA	NA	NA	11
Laflamme et al2	2	2	2	2	0	2	2	0	NA	NA	NA	NA	12

NA – Not Applicable in non-comparative studies.

0 – not reported, 1 – reported but inadequate, 2 – reported and adequate.

3. Observations and results

3.1. Study characteristics

Of the 12 studies included in our review, 11 were retrospective while Wang et al.¹⁴ was a prospective study in which patients were given a choice to choose the plate for fixation. 5 of the studies compared the reconstruction plate with the anatomical plate while the rest were conducted using only either of the plates. The minimum follow up in all the studies was for 1 year, while some studies followed their patients up to 5 years.¹

3.2. Patient characteristics

A total of 583 patients were analysed for intra operative and post operative parameters. Of these, 321 patients were fixed with anatomical buttress plates while the rest 262 were fixed with reconstruction plates. 442 (75.8 %) patients were males, and 141 (24.2 %) were females. The weighted mean age was 55.45 years.

3.3. Operative time

Pooled analysis of operative time revealed a mean of 173.9 min [95 % CI, 145.3–202.3] with a high heterogeneity [p = 0.000, I² = 98.7 %]. After further analysis and meta-regression this heterogeneity was independent of the choice of implant, age or gender. Subgroup analysis revealed a higher mean estimate in the reconstruction plate subgroup, but this was not significant [Fig. 2].

Fig. 2.

Mean estimate for operative time.

When data extracted from comparative studies was used, a significant decrease in the operative time in the anatomical subgroup was noted with a mean difference of 58.01 min [95 % CI, 8.02–75.4] [p value = 0.007] [Fig. 3].

Fig. 3.

Mean estimate for operative time in comparative studies.

3.4. Blood loss

There was a statistically significant difference in the mean estimated blood loss on the basis of fixation strategy with a mean of 702.9 ml [95 % CI, 597.9–807.8] in the anatomical subgroup and a mean of 1213 ml [95 % CI, 867.4–1558.7] in the reconstruction plate subgroup [Fig. 4].

Fig. 4.

Mean estimate for Blood loss.

This finding was echoed when data from the comparative studies was analysed, with a mean difference of 654.2 ml [95 % CI, 227.5–1080.9] [p value = 0.003] [Fig. 5].

Fig. 5.

Mean estimate of Blood loss in comparative studies.

3.5. Length of stay

Only 2 studies [4 study groups] reported on the duration of length of stay. There was moderate heterogeneity [p = 0.001, I² = 81.5 %] in the pooled estimate for length of stay with a calculated mean of 22.5 days [95 % CI, 18.2–26.9]. Increasing age was seen to correlate with decreasing length of stay on meta-regression [p < 0.001] [Fig. 6].

Fig. 6.

(a) Mean estimate of length of stay; (b) Meta-regression of length of stay.

3.6. Quality of reduction

Matta's criteria were the most common method to report on quality of reduction in the study cohort. Pooled analysis revealed that 59.6 % [95 % CI, 46.3–72.9] of patients had perfect reduction according to this criteria; the heterogeneity for this estimate was high [p = 0.000, I² = 92.9 %]. On meta-regression and subgroup analysis, age, gender or fixation method could not explain the heterogeneity. Outlier values were observed in both the anatomical and the reconstruction plate groups in the study by Nicol et al.¹ [Fig. 7a].

Fig. 7.

(a) Mean estimate of quality of reduction; (b) Mean estimate of quality of reduction in comparative studies.

On analysis of comparative studies, there was no significant difference in the achievement of perfect reduction between the anatomical and reconstruction plate subgroups [Fig. 7b].

3.7. Clinical outcomes

Merle's scoring system was used by majority of authors to report on clinical outcomes post-surgery for quadrilateral plate fractures. Overall mean estimate of Excellent/Good reduction was 83.1 % [95 % CI, 77.8–88.3]; with a moderate heterogeneity [p = 0.013, I² = 54.3 %]. Age, gender and fixation method had no bearing on the clinical outcomes [Fig. 8].

Fig. 8.

Mean estimate of Clinical outcomes.

3.8. Complications

The mean rate of complications from the included studies was 18.4 % [95 % CI, 13.1–23.7], this estimate had moderate heterogeneity [Fig. 9a].

Fig. 9.

(a) Mean estimate of complications; (b) Mean estimate of complications in comparative studies.

When comparative studies were analysed, the rate of complications in the reconstruction subgroup was higher and this was seen to be approcaching statistical significance [p value = 0.07] [Fig. 9b].

3.9. THA conversion

The pooled mean calculated for conversion to THA was 4.3 % [95 % CI, 1.5–7.2]; this estimate had low heterogeneity [p = 0.67, I² = 0 %] [Fig. 10a]. Similarly, there was no difference in rates of THA conversion noted on comparative analysis [Fig. 10b].

Fig. 10.

(a) Mean estimate of conversion to THA; (b) Mean estimate of conversion to THA in comparative studies.

3.10. Risk of bias

All the studies included in the review were scored as per the MINORS criteria [Table 3]. The comparative studies were given a score out of 24 while the others were given a score out of 16. Most of the studies had a moderate to high risk of bias. Studies by Wu et al.¹² and Wang et al.¹⁴ had a low risk of bias.

3.11. Operative technique

Out of the 12 studies which were included, 4 studies used anatomical plates, 4 used reconstruction plates and remaining 4 were comparative studies. All the surgeries were performed using either the ilio-inguinal approach, the Stoppa's approach, or the lateral rectus split approach. In the recon plate group, the surgeon had to contour the plate intra-operatively and the plate was positioned either suprapectineally or infrapectineally.

It must be noted that plates used in the anatomical plate group were different in each study and had their own advantages. Fan et al.²² developed the Anatomical Integrative Acetabular Plate (AIAP). The plate consists of 3 parts: an acetabular anterior column (from the greater sciatic notch to the pubic symphysis), an acetabular posterior column (from the greater sciatic foramen to the ischial spine), and a transverse bar (connecting the two columns) to provide triangular stability. 4 winged branches which diverge from the plate provide additional stability.

Wan et al.¹⁸ introduced the novel infrapectineal buttress plate (NIBP) which was composed of the curved infra-pectineal main plate and the quadrilateral surface blocking plate. The plate was long (16 holed) and the holes 4–7 and 10–12 are not supposed to be screwed to prevent joint penetration. It functioned similar to the iliosciatic and ischiopubic plates together.

The Acetabular fracture reduction internal fixator (AFRIF), as developed by Zha et al.²¹ consisted of five components. These include two segmental plates for the ilium and the inner wall with the latter having an extended arm with rachet. The other componenets are an arm to connect the ratchet, a set bolt and a pawl. They together form a unidirectional articulated joint. Tightening of the bolt controls the angle between the segmental plates and helps to maintain the reduction and fixation.

Sen et al.¹¹ developed the Anatomical Quadrilateral Plate (AQP) to match the anatomy from the supero-medial surface. It comprises of a curved central beam, matching the pelvic brim which is notched proximally for the sciatic buttress. It is twisted distally to fit over the pubic ramus. There is larger hole in the beam which allows for the passage of the dual cortical purchase nut. It also has 2 flanges which extend into the true pelvis to support the posterior column and anterior part of the quadrilateral plate. The flanges are separated, allowing easier insert of plate with reduction clamps in situ. A flange on the opposite site provides additional screw purchase options on the pelvic brim. The plate available in multiple sizes with hole distribution in accordance with plate size.

Kwak et al.¹³ and Nicol et al.¹ used the anatomical supra-pectineal plate developed by Stryker, Selzach Switzerland. Wang et al.¹⁴ used 3-D printed patient specific plates which could be placed at the pelvic brim with a triangular quadrilateral surface support. It also had 3 flanges for additional screw fixation. Wu et al.¹² used a titanium plate with a broader quadrilateral region for better screw placement.

The above observations highlight the fact that multiple plate options are available and have been used to buttress the quadrilateral plate [Fig. 11, Fig. 12].

Fig. 11.

Diagram depicting fixation of acetabular fracture using the anatomical plate.

Fig. 12.

Pre-operative and post operative X-rays of a patient with quadrilateral plate fracture fixed with anatomical plate.

4. Discussion

The results of our study involving 583 patients indicate that quadrilateral plate fractures are common in adults with an average age of 55 years and males are much more commonly affected (3:1) than women. It was noted that fixation of the quadrilateral plate using anatomical plates was found to have a shorter operative duration with the plate probably needing less molding and serving as a reduction tool. It also led to lesser blood loss. Long term outcomes of quadrilateral plate fractures depend on the quality of reduction and a good reduction irrespective of the implant choice leads to better clinical outcomes.

The exact definition of the quadrilateral surface is ambiguous, and so is its treatment. ElNahal et al.²⁵ defined it as the trapezoid between the pelvic brim superiorly, the greater sciatic notch posteriorly, a line joining the ischial spine and obturator foramen inferiorly, the obturator foramen anteriorly. Guyton and Perez²⁶ described it as the medial acetabular wall which prevents medial displacement of the femur head.

Acetabular fractures in the elderly tend to have a different fracture pattern as compared to the young. Approximately 50 % of the cases have associated quadrilateral plate fractures.^25,27

Due to its proximity of the femoral head and thinner cortical thickness in comparison to the acetabular columns, the quadrilateral surface does offer much for stable anchorage of the plate screws, affecting implant stability. The concept of buttress plating the fracture was introduced by Mears et al.²⁸ to prevent intra articular screw penetration. If multiple screws are put in the quadrilateral region, protrusion may ensue due to the weak purchase. This increases the chance of screw loosening and secondary displacement.²⁹ This, along with its deep location, and close proximity to major neurovascular structures makes their surgical management challenging. At the same time, it must not be forgotten that the reduction of the quadrilateral plate fracture directly correlates with better surgical outcomes. Failure to achieve a good reduction and fixation would eventually lead to a higher incidence of post-traumatic arthritis.³⁰

Literature on surgical management of quadrilateral plate fractures with buttress plates is scarce. Recent times have brought forward newer implant options for these fractures and raised the necessity to understand if their theorised benefits were replicated in clinical practice. Our literature search revealed only 12 studies which fulfilled our inclusion criteria. Amongst these, only 4 directly compared the anatomical and reconstruction plates. This review and meta-analysis was conducted to ascertain how the choice of plate affected the perioperative and postoperative outcome variables. Pooled estimates of the 583 patients with quadrilateral plate fractures enabled us to report the mean operative time, blood loss, length of stay, reduction as per Matta's criteria, clinical outcomes on the basis of Merle D'Aubigne and Postel score and complication rates.

The mean operative time in our study was 173.9 min and the subgroup which was treated with reconstruction plates tended to have higher operative time. There was high heterogeneity in the data which could stem from the lack of standardization of what was included in the operative time and multiple different centres being involved in the analysis. However, when only comparative studies were taken, the difference was significant with a difference of almost 1 h (p = 0.007). This can be explained by the fact that repeated shapings are not needed for anatomical plates and an appropriate plate can be selected preoperatively on a 3-D model or directly intra operatively. Also the drilling and screw placement is more standardised.¹⁴ The difference when pooled analysis and comparative analysis could be explained on the basis that surgeons who were using reconstruction plates exclusively would be more proficient in their molding intraoperatively, thereby needing lesser time, versus surgeons using both types of plates. Saving time intraoperatively also saves blood lost, with there being a statistically significant (p = 0.003) difference of over 500 ml excess loss in the reconstruction plate subgroup. Preventing excess blood loss is quintessential of the goals of an orthopaedic surgery especially in the geriatric age group. These findings echo with the principles on which the anatomical plate was invented.

The length of stay was mentioned in only 2 studies^1,12 and was found to be similar in both the groups. Older age was associated with a shorter hospital stay. This could be because the two studies were performed at different centres with different treatment protocols.

Notably, the radiological outcomes via the Matta reduction criteria and the clinical outcomes via the Merle score did not show any statistical differences. Almost 60 % of the patients had perfect reduction as per the Mattas criteria and more than 80 % of the patients reported an excellent or good outcome. A perceived benefit of using the anatomical plate was as a reduction tool, such that when the plate is applied, it spreads the force over the quadrilateral surface and indirectly corrects the femoral head position. However, this doesn't appear to be proven as reconstruction plates were equally effective.

The rate of complications in acetabular surgery is high, approaching almost 20 %. Subgroup analysis revealed that there was a tendency for higher complications in the reconstruction plate group which could be because of the longer operative duration. This however was not statistically significant.

4.1. Limitations

Our study has certain limitations: Most of the studies included were retrospective in nature and only four were comparative. The surgeries were performed via different approaches and these could play a role in fracture visualization and reduction. The anatomical plates used in each study were built in the respective regions where the studies were performed and did vary in designs. However, the authors would like to point out that this also serves as a strength as the bony anatomy varies amongst people of different races in different parts of the world and an anatomical plate needs to be curated for the population of its region.

5. Conclusion

Our study seems to indicate that the anatomical plate is better than the reconstruction plate for fixation of quadrilateral plate fractures in terms of intraoperative blood loss and operative time. However, the long term outcomes are equivocal.

This opens the avenue for future research on this topic. Prospective studies and randomized control trials need to be conducted to reaffirm our findings and shed further clarity.

CRediT authorship contribution statement

Ansh Gupta: Investigation, Resource collection, Data curation, Writing – original draft. Parth Bansal: Investigation, Resource collection, Writing – review, Formal analysis. Vishal Kumar: Resources, Validation, Visualization, Formal analysis. Sameer Aggarwal: Conceptualization, Supervision, Project administration.

Ethical statement

None.

Consent

Informed consent was not obtained from patients since this is a systematic review of literature already published and no new patients were enrolled in the study.

Funding statement

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

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.