A novel stacked double-plate fixation with quadrilateral surface buttress screws for osteoporotic acetabular fractures in elderly patients: a prospective pilot case series study evaluating clinical and radiological outcomes

Abstract

Background

Acetabular fractures in the elderly present unique challenges due to osteoporotic bone, comminution, and frequent involvement of the quadrilateral surface (QLS) and anterior column. Conventional fixation often fails in this population, leading to hardware complications and secondary displacement. This prospective pilot study evaluates the clinical and radiological outcomes of a novel stacked double-plate technique combined with QLS buttress screws in geriatric patients.

Methods

Twelve consecutive patients aged ≥ 70 years with displaced acetabular fractures involving the anterior column and QLS were treated between 2018 and 2022. All patients underwent the stacked double-plate technique with QLS buttress screws via a Modified Stoppa approach. Operative time, blood loss, complications, radiological reduction (Matta criteria), fracture union, and postoperative functional outcomes were prospectively recorded.

Results

The cohort included 12 patients (mean age 74 ± 5 years; range 70–85). Fracture patterns were anterior column with quadrilateral plate (n = 6), associated both-column fractures (n = 4), and transverse fractures (n = 2). Mean operative time was 145 ± 18 min, and mean blood loss was 280 ± 65 mL. At a mean follow-up of 14 months (range 6–30), all fractures achieved union. Reduction quality was anatomical in 10 patients and satisfactory in 2. Final functional outcomes were favorable, with a mean HHS of 88 ± 5 (95% CI: 83–93) and mean total WOMAC of 12 ± 4 (95% CI: 8–16). No complications or hardware failures were observed.

Conclusion

In this prospective pilot case series, the stacked double-plate technique with QLS buttress screws was feasible, provided stable fixation, and was associated with stable fixation and satisfactory functional outcomes in elderly patients with osteoporotic acetabular fractures. These preliminary findings should be interpreted cautiously due to the limited sample size, absence of a control group, and relatively short follow-up. Further studies with larger cohorts, comparative designs, and biomechanical validation are warranted.

Introduction

Acetabular fractures in the elderly are challenging due to osteoporotic bone, complex fracture patterns, and frequent anterior column–quadrilateral surface involvement. Typically caused by low-energy falls, compromised bone quality limits conventional fixation, increasing the risk of reduction loss, hardware failure, and early post-traumatic arthritis [1–5]. Achieving and maintaining anatomical reduction, especially of the quadrilateral surface, is consistently associated with better functional outcomes and fewer complications [5–10].

Although numerous fixation strategies have been proposed, including locking constructs, infrapectineal plates, and patient-specific implants, each method has limitations in severely osteoporotic bone. Many techniques have been associated with early screw loosening, secondary displacement, or mechanical failure, while others are hampered by cost, limited accessibility, or increased technical demands [6–9]. These challenges highlight the need for a fixation strategy that enhances construct stability while remaining reproducible and accessible.

Despite the availability of infrapectineal plates, locking constructs, and patient-specific implants, no consensus exists regarding the optimal fixation strategy for severely osteoporotic anterior column–quadrilateral surface fractures. Many currently available techniques focus either on quadrilateral surface buttressing or enhancement of screw fixation, but few integrate both principles into a single construct specifically designed for fragile osteoporotic bone. Consequently, there remains a need for a simple, reproducible, and widely applicable fixation method that improves construct stability while maintaining technical feasibility in routine clinical practice.

Instead of treating quadrilateral plate fixation and osteoporotic screw purchase separately, recent biomechanical insights advocate combining buttress principles with additional fixation points to enhance construct stiffness and reduce micromotion [7, 11–14]. Stacked double plating may increase cortical fixation, distribute loads across multiple bone corridors, and lessen reliance on fragile cancellous bone, potentially improving stability in osteoporotic fractures. However, a simple, reproducible, and mechanically reliable method for fragile bone remains lacking. This motivated the development of our stacked double-plate technique with quadrilateral buttress screws, which directs fixation into stronger periacetabular corridors to maintain reduction while remaining technically feasible for routine use. This technique combines three complementary fixation concepts: an S-shaped pelvic brim reconstruction plate, quadrilateral surface buttress screws directed through the plate, and stacked supplementary reconstruction plates that increase fixation points across multiple cortical regions. The novelty lies in the integration of these elements into a single construct designed specifically for osteoporotic anterior column–quadrilateral surface fractures.

The aim of this prospective pilot study was to evaluate the feasibility, radiological outcomes, and preliminary functional results of a novel stacked double-plate fixation construct supplemented with quadrilateral surface buttress screws in elderly patients with displaced osteoporotic acetabular fractures involving the anterior column and quadrilateral surface. We hypothesized that this construct would provide a clinically feasible method for maintaining fracture reduction and achieving stable fixation in osteoporotic bone while allowing satisfactory early functional recovery.

Patients & methods

We conducted a prospective observational study at University Hospital from January 2018 through December 2022, following ethical approval from the institutional review board [N-4-202]. During the study period, 25 elderly patients with acetabular fractures were evaluated. All consecutive eligible patients meeting the predefined inclusion criteria were included in the study to minimize selection bias, resulting in a final cohort of 12 patients.

All patients aged 70 years or older presenting with displaced acetabular fractures involving both the anterior column and quadrilateral surface, in the presence of osteoporotic bone quality, were considered eligible for inclusion. Osteoporotic bone quality was determined based on preoperative radiographic evidence of osteoporosis together with intraoperative assessment of diminished screw purchase and cortical fragility. DXA densitometry and CT-derived Hounsfield unit measurements were not routinely available during the study period and therefore were not incorporated into the eligibility criteria. Fractures were classified preoperatively according to the Letournel and Judet system, documented for consistency and reproducibility. Postoperative CT scans were obtained selectively in cases where plain radiographs were inconclusive or when implant position required additional confirmation, rather than as part of the routine postoperative assessment.

We excluded 13 patients with pathologic fractures, those requiring acute primary total hip arthroplasty with unreconstructable articular surface, and patients with active infection. Patients with fracture patterns not involving both the anterior column and quadrilateral surface or without evidence of osteoporotic bone quality were also excluded. All participants provided written informed consent for study participation and follow-up. The relatively modest inclusion rate over the study period reflects the strict predefined eligibility criteria rather than the overall incidence of geriatric acetabular fractures. Only patients with displaced fractures involving both the anterior column and quadrilateral surface in the presence of osteoporotic bone quality were eligible for inclusion. A patient flow diagram illustrating patient screening, reasons for exclusion, and final study enrollment has been added (Fig. 1).

Fig. 1.

Flow diagram of patient screening, eligibility assessment, exclusions, and final study inclusion

All procedures were performed under general anesthesia using the modified Stoppa approach, which provides direct exposure of the QLS and anterior column. After achieving meticulous reduction of the articular surface and QLS, a pre-contoured 3.5- or 4.5-mm non-locked reconstruction plate was positioned along the medial pelvic brim as the primary fixation plate. This plate was shaped in an S-configuration to align its central portion with the pelvic brim and its distal segment along the inner ilium. This configuration enabled the distal plate segment to function as a dynamic lever: when pushed or retracted laterally during final tightening, the buttress screws generated additional controlled compression against the QLS. Importantly, this provided effective medial buttressing without requiring strong screw purchase in osteoporotic bone, as stability was achieved through plate geometry and directed screw vectors rather than bone density.

To stabilize the QLS, buttress screws (3.5, 4.5, cortical or cancellous) were inserted through the plate to exit medially, traverse the QLS, and engage the pelvic cortex. Screw placement was performed under fluoroscopic guidance using standard pelvic inlet, outlet, obturator and iliac oblique views to confirm extra-articular positioning and avoid intrapelvic or intra-articular penetration. Screw trajectories followed established periacetabular osseous corridors while maintaining quadrilateral surface buttressing. The screws were inserted through the reconstruction plate close to the pelvic brim and directed along the pelvic surface of the quadrilateral plate rather than through the articular region. This extra-osseous trajectory allowed the screw shaft to act as a buttress against the medially displaced quadrilateral surface while avoiding joint penetration. Final screw position and trajectory were verified fluoroscopically in multiple planes before definitive tightening. To enhance rotational stability and maintain reduction, two or three buttress screws with different orientations were used when required. This produced characteristic three-point anchorage—initial tightness, a brief “give,” and a final firm endpoint—facilitating controlled reduction with two or three differently angled screws to prevent rotational displacement.

After the primary plate was secured, a second 3.5-mm reconstruction plate, one or two according to intraoperative needs, fracture configuration, and osteoporotic state, was contoured and stacked directly over it using shared or independent screw holes. The second plate acted as a stabilizing frame, preventing screw back-out by providing additional anchorage points distributed around the main plate. By engaging multiple, widely spaced cortical regions—including the iliac crest, pubic body, and sciatic buttress—the construct covered a larger surface area and improved fixation in osteoporotic bone.

Patients were evaluated clinically and radiographically at 6 weeks, 3 months, 6 months, and 12 months, and annually when feasible. Standard anteroposterior and Judet radiographs were obtained at each visit. Reduction quality was graded using the Matta radiological criteria, assessed independently by two fellowship-trained pelvic trauma surgeons. Interobserver agreement was calculated using Cohen’s kappa statistic, with a kappa value of 0.82 indicating excellent agreement. Postoperative CT scans were performed selectively only in cases where plain radiographs were inconclusive or to verify hardware placement.

Functional outcomes were assessed using the Harris Hip Score (HHS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at postoperative follow-up points (6 months, 12 months, and final follow-up). Functional outcome assessments were performed by an independent evaluator who was not involved in the surgical treatment.

All intraoperative and postoperative complications, including infection, neurovascular injury, thromboembolic events, heterotopic ossification, reoperation, mortality, and conversion to total hip arthroplasty, were prospectively recorded. Follow-up completion was recorded at each predefined time point (6 weeks, 3 months, 6 months, 12 months, and final follow-up), and the number of patients available for functional assessment was documented at each interval.

All patients were mobilized immediately with partial weight bearing as tolerated. Full weight bearing was allowed between 8 and 12 weeks, individualized according to radiographic healing and patient tolerance. Standard institutional protocols were followed for thromboprophylaxis, antibiotic prophylaxis, and multimodal pain management.

Results

25 elderly patients with acetabular fractures were screened for eligibility. A total of 12 geriatric patients with displaced acetabular fractures involving the anterior column and QLS fulfilled the inclusion criteria and included in this prospective series. The cohort consisted of 7 females and 5 males, with a mean age of 74 years (range 70–85). Injury mechanisms included low-energy falls in 8 patients and motor vehicle accidents in 4 patients. Fracture patterns included anterior column with quadrilateral plate (n = 6), associated both columns (ABC, n = 4), or transverse (n = 2). All patients were treated using the stacked double-plate technique with QLS buttress screws. In the four cases with posterior column involvement, the displacement was reduced and stabilized using a posterior column screw. All 12 patients were available for functional outcome assessment at all follow-up intervals. The mean operative time was 145 ± 18 min (range 120–175 min) and mean estimated blood loss was 280 ± 65 mL (range 200–400 mL) (Table 1).

Table 1.

Demographics, surgical data, radiological outcomes, and functional recovery, Subgroups for age, fracture pattern, and reduction quality included

Parameter	Overall / Subgroup	Functional Outcome (HHS, mean ± SD)	WOMAC Total (mean ± SD)	Notes / Correlation
Age (years), mean ± SD (range)	74 ± 5 (70–85)	70–74: 89 ± 4 75–79: 87 ± 5 ≥ 80: 84 ± 3	12 ± 4	Older age associated with slightly lower recovery
Sex, n	Female 7, Male 5	Female: 87 ± 5 Male: 89 ± 4	Female: 12 ± 3 Male: 11 ± 3	No significant differences
Mechanism of injury, n	Low-energy fall 8, MVA 4	Low-energy: 87 ± 5 MVA: 88 ± 4	Low-energy: 13 ± 3 MVA: 12 ± 2	Similar outcomes between mechanisms
Fracture pattern, n	AC-QLP 6, ABC 4, Transverse 2	AC-QLP: 88 ± 4 ABC: 89 ± 4 Transverse: 86 ± 3	AC-QLP: 12 ± 3 ABC: 11 ± 3 Transverse: 14 ± 2	Good outcomes across all patterns, ABC slightly highest
Operative time (min)	145 ± 18 (120–175)	—	—	No correlation with outcomes
Estimated blood loss (mL)	280 ± 65 (200–400)	—	—	No correlation with HHS/WOMAC
Matta reduction, n	Anatomical 10, Satisfactory 2	Anatomical: 89 ± 4 Satisfactory: 83 ± 3	Anatomical: 11 ± 3 Satisfactory: 16 ± 2	Anatomical reduction strongly improves outcomes
Interobserver agreement	κ = 0.82	—	—	Excellent reliability
Fracture union, n	12/12	—	—	All fractures united
Secondary displacement / hardware failure	None	—	—	Stable construct in osteoporotic bone
Complications	None	—	—	No infection, neurovascular injury, VTE, or reoperation
HHS (mean ± SD, 95% CI)	6 mo: 72 ± 6 ,12 mo: 85 ± 5 Final: 88 ± 5 (83–93)	—	—	Continuous functional improvement
WOMAC Total (mean ± SD, 95% CI)	6 mo: 28 ± 6, 12 mo: 18 ± 5 Final: 12 ± 4 (8–16)	—	—	Marked pain and disability reduction
QLS buttress screw placement	Medial divergence vs. parallel	All stable	—	Trajectory did not affect reduction or union

At a mean follow-up period 14 ± 7 months, with a median follow-up of 14 months (IQR, 11–18 months; range, 6–30 months), all fractures had united radiographically. According to the Matta criteria, reduction quality was anatomical in 10 patients and satisfactory in 2. Interobserver agreement for radiographic reduction assessment was excellent, with a Cohen’s kappa value of 0.82. No secondary displacement, screw back-out, or implant failure was observed (Figs. 2, 3, 4 and 5 representing case examples).

Fig. 2.

Sawbone models demonstrate the stacked double-plate technique. A Medial placement of the primary reconstruction plate with ideal positioning of buttress screws. B Final construct showing two contoured reconstruction plates stacked over the primary plate to enhance fixation stability. C Intraoperative reduction steps using the stacked double-plate technique: application of the first S-shaped contoured reconstruction plate onto the symphysis pubis/anterior column, reduction of the anterior column fracture, reduction of the quadrilateral surface maintained with a medially directed buttress screw through the plate, lateralization of the distal plate end to enhance compression across the quadrilateral surface, and final stabilization with one or two additional reconstruction plates stacked over the primary plate to increase fixation points and prevent screw back-out across the iliac wing

Fig. 3.

Patient with a left associated both column acetabular fracture. A, B, C Preoperative radiograph and 3D CT images demonstrating the fracture pattern with involvement of the quadrilateral surface. D, E, F Final follow-up radiographs showing maintained reduction and stable fixation using the stacked double-plate construct with quadrilateral plate buttress screws and posterior column screws

Fig. 4.

Patient with a left anterior column with quadrilateral surface acetabular fracture. A, B Preoperative radiograph and 3D CT images demonstrating the fracture pattern with involvement of the quadrilateral surface. C, D, E Final follow-up radiographs showing maintained reduction and stable fixation using the stacked double-plate construct with quadrilateral plate buttress screws

Fig. 5.

Patient with a right acetabular fracture anterior column with quadrilateral surface acetabular fracture. A, B, C Preoperative radiograph and 3D CT images demonstrating the fracture pattern with involvement of the quadrilateral surface. D, E, F Final follow-up radiographs showing maintained reduction and stable fixation using the stacked double-plate construct with quadrilateral plate buttress screws

Functional scores at follow-up intervals showed that mean HHS improved from 72 ± 6 at 6 months to 85 ± 5 at 12 months and 88 ± 5 at final follow-up (95% CI: 83–93). Mean total WOMAC score improved from 28 ± 6 at 6 months to 18 ± 5 at 12 months and 12 ± 4 at final follow-up (95% CI: 8–16). Overall, patients achieved substantial functional recovery, with most returning to independent ambulation and no limitations attributable to mechanical failure or loss of fixation. No intraoperative or postoperative complications occurred, including infection, neurovascular injury, thromboembolic events, or reoperation. Hardware-related complications such as screw loosening, plate migration, or mechanical failure were absent. The QLS buttress screw effectively maintained medial support, contributing to stable fixation even in severely osteoporotic bone.

Given the limited sample size and statistical power, all subgroup analyses were considered exploratory and were not intended for formal statistical comparison. To enhance transparency, individual patient-level demographic, surgical, radiological, and functional outcome data are presented in Table 2. Descriptive review of these patient-level data suggested that patients with anatomical reduction generally achieved higher functional scores than those with satisfactory reduction, whereas fracture pattern, mechanism of injury, sex, and age did not demonstrate consistent associations with clinical outcomes. These observations should be interpreted cautiously and considered hypothesis-generating only.

Table 2.

Patient-level demographic, surgical, radiological, and functional outcomes

Patient	Age	Sex	Fracture Pattern	Injury Mechanism	Operative Time (min)	Blood Loss (mL)	Reduction (Matta)	Union	HHS Final	WOMAC Final	Complications	THA Conversion
P1	72	F	AC-QLP	Fall	140	260	Anatomical	Yes	90	10	None	No
P2	74	M	ABC	MVA	150	300	Anatomical	Yes	88	12	None	No
P3	70	F	AC-QLP	Fall	135	240	Satisfactory	Yes	83	16	None	No
P4	78	F	ABC	Fall	155	320	Anatomical	Yes	89	11	None	No
P5	76	M	Transverse	MVA	145	280	Anatomical	Yes	86	14	None	No
P6	80	F	AC-QLP	Fall	160	350	Satisfactory	Yes	82	17	None	No
P7	73	M	ABC	Fall	142	270	Anatomical	Yes	90	10	None	No
P8	75	F	AC-QLP	Fall	138	250	Anatomical	Yes	87	12	None	No
P9	77	M	Transverse	MVA	148	290	Anatomical	Yes	85	14	None	No
P10	74	F	ABC	Fall	150	300	Anatomical	Yes	89	11	None	No
P11	81	F	AC-QLP	Fall	170	400	Satisfactory	Yes	84	18	None	No
P12	70	M	ABC	MVA	130	200	Anatomical	Yes	91	9	None	No

Discussion

Geriatric acetabular fractures continue to pose a major challenge due to the combination of osteoporotic bone, complex fracture patterns, and the predominance of low-energy mechanisms in the elderly population. These fractures frequently involve the anterior column and quadrilateral surface (QLS), where diminished bone density compromises screw purchase and increases the risk of fixation failure [1–3]. Achieving stable fixation in this demographic is therefore more difficult than in younger patients who sustain high-energy acetabular injuries.

The clinical importance of obtaining accurate anatomical reduction in geriatric acetabular fractures has been repeatedly emphasized in recent literature. High-quality reductions are associated with superior postoperative hip function and patient-reported outcomes [4, 5]. These findings underscore the limitations of conventional fixation in osteoporotic bone, where maintaining anatomical reduction remains challenging. Published series of elderly patients treated with standard ORIF report rates of secondary displacement or hardware complications ranging from 10 to 25%, highlighting the difficulty in achieving stable fixation in this population [6, 7]. Certain fracture patterns in elderly patients inherently lack structural integrity and may require enhanced fixation strategies [6, 7].

Augmented fixation constructs, such as infrapectineal or suprapectineal QLS plates, have been shown in finite-element studies to reduce displacement and improve stress distribution compared with standard reconstruction plates [8]. Patient-specific 3D-printed plates and anterior pelvic wall locking plates offer theoretical mechanical advantages [9, 10], though their use remains technically demanding. Direct fixation of the QLS generally yields better outcomes than indirect reduction alone [11]. Minimally invasive options, including percutaneous screws and robot-assisted placement [12, 13], may be appropriate for low-displacement fractures but are less applicable to displaced or comminuted anterior column–QLS patterns. Biomechanical evidence consistently suggests that plate constructs outperform screw-only methods under cyclic loading [14]. Surgical approaches, such as the modified lateral rectus, provide improved access to the anterior column and QLS while minimizing morbidity in elderly patients [15].

Against this background, the rationale for the stacked double-plate technique becomes apparent. The construct is designed to theoretically maximize plate–bone contact, improve force distribution across multiple cortical segments, and enhance buttressing of the QLS in osteoporotic bone. The addition of a second contoured plate may provide additional rigidity and screw security by allowing fixation into stronger cranial and caudal cortices, offering reinforcement without claiming proven mechanical superiority. The novelty of this construct lies in its proposed synergistic combination of medial column buttressing, quadrilateral surface screw control, and load-sharing reinforcement through stacked plating, which may help address fixation challenges encountered in osteoporotic acetabular fractures. These potential mechanical advantages remain theoretical and require validation through dedicated biomechanical studies.

The primary reconstruction plate is contoured into an S-shaped configuration to conform to the pelvic brim and inner ilium. This geometry is intended to allow the plate to function as a lever and may generate controlled compression across the quadrilateral surface during final tightening. Lateral tension through the distal limb is hypothesized to provide medial buttressing largely independent of bone quality. Accordingly, construct stability is hypothesized to result from plate contouring and strategic screw vector orientation, potentially reducing reliance on weak osteoporotic cancellous bone.

Buttress screws are oriented medially to traverse the QLS and engage the pelvic cortex, providing potentially stable three-point purchase. Divergent trajectories enhance rotational control and assist reduction, potentially improving fixation even when cancellous bone is poor. A second, stacked plate expands fixation into stronger cortical regions of the iliac crest, pubic body, and sciatic buttress. Although not objectively quantified, this supplemental plate is intended to distribute mechanical loads, reduce screw back-out risk, and improve resistance to deformation, creating a cage-like construct that may redirect forces away from fragile osteoporotic bone toward stronger pelvic corridors. Because construct augmentation was individualized according to fracture characteristics and bone quality, the influence of plate number on clinical and radiographic outcomes could not be evaluated in this small pilot series and requires further investigation.

In this pilot prospective study, 12 elderly patients treated with the stacked double-plate construct achieved radiographic union in all cases, with anatomical reduction in 10 patients and satisfactory reduction in 2. Postoperative functional outcomes, including HHS and WOMAC scores, were favorable and comparable to previously reported outcomes in elderly cohorts treated with conventional ORIF [4–6]. No secondary displacement, screw back-out, or implant failure occurred. Patients achieved early mobilization and returned to near-normal function without complications directly attributable to the fixation technique. The proposed technique should currently be considered primarily for elderly patients with displaced anterior column–quadrilateral surface acetabular fractures and compromised bone quality. Its role in other fracture configurations remains to be established. Postoperative CT scans were performed selectively rather than routinely; therefore, subtle residual incongruities or minor implant malposition may not have been detected.

Against these encouraging findings, comparison with contemporary literature is important. Wu et al. reported favorable functional outcomes following ORIF of quadrilateral plate fractures in elderly patients, with most patients achieving good or excellent clinical results [5]. Similarly, Panella et al. reported mean HHS values of approximately 88 following ORIF of quadrilateral surface fractures in elderly patients, emphasizing the importance of stable reduction and fixation [4]. Rommens et al. demonstrated satisfactory outcomes after ORIF in older patients but observed subsequent conversion to total hip arthroplasty in cases with imperfect reduction [6]. In contrast, none of the patients in the present series required secondary arthroplasty during follow-up. Furthermore, Panella et al. demonstrated that direct fixation of the quadrilateral surface was associated with lower rates of post-traumatic arthritis compared with indirect fixation techniques [11], which may support the rationale for direct quadrilateral surface buttressing as utilized in our construct. Emerging technologies such as robot-assisted fixation have also demonstrated functional outcomes comparable to conventional fixation methods while potentially improving surgical accuracy [13]. However, direct comparisons should be interpreted cautiously because of differences in fracture patterns, patient characteristics, follow-up duration, and study design. Overall, the clinical and radiological outcomes observed in the present study are broadly consistent with those reported in contemporary series of elderly acetabular fracture fixation [4–6, 11, 13].

This study’s strengths include prospective data collection, standardized surgical technique, and consistent radiographic and functional assessment. The small sample size limits statistical inference and the ability to accurately estimate complication rates; therefore, the absence of complications should be interpreted with caution. Because of the small cohort, subgroup findings should be interpreted as descriptive observations rather than formal comparative analyses. The absence of a control group limits direct comparison with alternative fixation techniques and precludes definitive conclusions regarding relative efficacy. The relatively short and heterogeneous follow-up period limits assessment of long-term outcomes, including post-traumatic arthritis, late fixation failure, and conversion to total hip arthroplasty. The absence of biomechanical testing and the lack of comparison with conventional single-plate fixation preclude conclusions regarding mechanical superiority or relative efficacy. In addition, osteoporotic bone quality was defined using pragmatic radiographic and intraoperative criteria rather than objective DXA or CT Hounsfield unit measurements, which may limit reproducibility across institutions.

In summary, contemporary management of geriatric acetabular fractures focuses on anatomical reduction, fracture-specific fixation, and ensuring construct stability in osteoporotic bone. The stacked double-plate technique, reinforced with a QLS buttress screw, provides a conceptually sound that appears clinically feasible strategy for stabilizing anterior column–QLS fractures in elderly patients. Future comparative studies, including dedicated biomechanical validation, are warranted to further define its role among fixation strategies for this high-risk population.

Conclusion

Geriatric acetabular fractures remain a major surgical challenge due to osteoporosis, comminution, and complex anterior column–quadrilateral surface involvement. Successful management requires individualized treatment planning that considers fracture morphology, bone quality, and patient comorbidities, along with clear preoperative counseling regarding expected outcomes.

In this prospective pilot series, the stacked double-plate technique—supplemented with a quadrilateral surface buttress screw—demonstrated feasibility and safety, with encouraging but preliminary clinical outcomes in elderly patients with severely osteoporotic acetabula. The construct demonstrated stable postoperative behavior with no observed hardware-related complications or loss of reduction in this limited cohort. These findings suggest that the technique is a feasible and reproducible technical option, although the absence of a comparative control group precludes conclusions regarding its relative effectiveness or superiority over existing fixation methods.

Based on the findings of this prospective pilot case series, the proposed technique represents a practical, conceptually reinforced augmentation strategy for fragility acetabular fractures, complementing existing anatomical, locking, and infrapectineal plating options. However, given the pilot nature and limited sample size of this study, these findings should be interpreted as exploration. Future research, including larger sample sizes, comparative clinical cohorts, and dedicated biomechanical studies, is required to confirm these preliminary findings and to clarify the role of this technique among evolving fixation strategies for this high-risk population.

Authors’ contributions

All authors contributed to the study conception and design. M.ab . : Conceptualization of the study, design of methodology, patient recruitment, surgical procedures, data collection, interpretation of results, manuscript drafting, and critical revision for intellectual content. A.F and M.F: Data analysis, statistical evaluation, radiological assessment, preparation of tables and figures, manuscript drafting, and review for accuracy and clarity.

Funding

The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.

Data availability

The datasets used and/or analyzed during the current study available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of orthopaedic department of Cairo University.

Informed consent was obtained from all individual participants included in the study.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.