Custom-Made Acetabular Implants in Complex Revision Total Hip Arthroplasty: A Systematic Review (2000–2025)

Abstract

Background/Objectives: Severe acetabular bone loss, particularly Paprosky type IIIA and IIIB defects and pelvic discontinuity, represents a major challenge in revision total hip arthroplasty (rTHA). Custom-made acetabular implants offer a patient-specific reconstructive option when conventional techniques may not provide adequate fixation. This systematic review evaluated the clinical outcomes, implant survivorship, complication profile, and methodological quality of custom-made acetabular implants used in complex rTHA. Methods: A systematic literature search of PubMed, ScienceDirect, and Web of Science was performed to identify eligible studies published between January 2000 and December 2025 reporting outcomes of custom-made acetabular implants in rTHA. Thirty-six eligible clinical publications were included in the qualitative synthesis. Potentially overlapping or longitudinally related patient cohorts were identified and not treated as independent populations when interpreting outcomes. Data extraction included study design, patient and defect characteristics, implant type, follow-up duration, implant survivorship, functional outcomes, complications, and re-revision. Methodological quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS). Results: Reported implant survivorship ranged from 72.4% to 100% across the included studies, with several series reporting survivorship above 90% at mid- to long-term follow-up. Functional outcomes generally improved following reconstruction, while aseptic loosening was relatively uncommon. Infection and instability were important causes of reoperation and implant failure. Methodological quality was variable: among the 34 non-comparative publications, MINORS scores ranged from 6 to 13 out of 16, while the two comparative publications scored 15/24 and 14/24. Considerable heterogeneity in patient populations, defect severity, implant design, follow-up duration, and outcome reporting precluded quantitative pooling. Conclusions: Custom-made acetabular implants represent a potential reconstructive option for carefully selected patients undergoing complex rTHA for severe acetabular bone loss and pelvic discontinuity. Published studies report favorable implant survivorship and improvements in functional outcomes; however, the evidence is derived predominantly from retrospective, non-comparative series and does not establish superiority over alternative reconstructive strategies. Prospective, multicenter, comparative investigations using standardized outcome definitions and longer follow-up are needed to better define long-term effectiveness.

1. Introduction

Total hip arthroplasty (THA) is one of the most effective procedures in contemporary orthopedic surgery, providing substantial improvements in mobility and quality of life for patients with advanced hip pathology [1]. In recent decades, however, the increase in primary THA has been accompanied by a corresponding rise in revision procedures [2]. Performing revision total hip arthroplasty (rTHA) remains technically demanding, particularly in the presence of substantial acetabular bone loss [3].

Severe acetabular defects may result from aseptic loosening, periprosthetic joint infection, recurrent dislocation, progressive osteolysis, or multiple previous revision procedures [2,3]. In complex cases, particularly Paprosky type III defects and pelvic discontinuity, restoring bone stock and achieving stable hip biomechanics are especially challenging [3,4]. Conventional reconstructive options such as jumbo cups, structural allografts, reinforcement rings, and cup-cage constructs may provide satisfactory results in selected cases but can be limited when residual host bone is severely compromised [3].

Advances in three-dimensional imaging, computer-aided design (CAD), and additive manufacturing have enabled the development of patient-specific acetabular implants tailored to individual anatomy [5]. These implants are typically designed using high-resolution computed tomography (CT) imaging, allowing detailed defect characterization, optimized implant geometry, and individualized screw trajectories [6,7]. Among the available designs, custom triflange components have received particular attention because they allow multiplanar fixation through the ilium, ischium, and pubis while facilitating restoration of the hip center of rotation [5,8].

Clinical experience with custom-made acetabular implants has expanded considerably over the last two decades, but the published evidence remains heterogeneous [5]. Most published studies are retrospective case series with relatively small patient cohorts, variable follow-up durations, and inconsistent reporting of functional outcomes, implant survivorship, and complications [5]. Technical and radiological investigations have also provided information on implant design, positioning accuracy, and bone integration, although these findings have not been consistently integrated into the clinical literature [6,7,9].

The aim of this systematic review was to synthesize the current evidence regarding custom-made acetabular implants used in complex revision total hip arthroplasty. The review focused on implant survivorship, functional outcomes, complications, re-revision rates, and methodological quality. Technical and radiological studies were considered separately to provide additional information on implant design and implantation accuracy.

2. Materials and Methods

2.1. Study Design and Reporting Standards

This systematic review was conducted in accordance with the PRISMA 2020 recommendations [10]. The aim was to identify and critically appraise clinical studies evaluating outcomes of custom-made acetabular implants—fabricated through 3D printing or CAD–CAM technology—in complex revision total hip arthroplasty (rTHA). The review protocol was outlined before data collection. Two investigators independently performed the search, screening, and data selection, with disagreements resolved by discussion until consensus was reached.

2.2. Search Strategy and Study Selection

This systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO; registration number CRD420261401358).

A systematic literature search was conducted in PubMed, Web of Science Core Collection, and ScienceDirect to identify studies evaluating custom-made acetabular implants in revision total hip arthroplasty. The search covered publications from January 2000 to December 2025 and was based on terms related to custom-made or patient-specific acetabular implants, revision total hip arthroplasty, severe acetabular bone loss, and pelvic discontinuity. The search strategy was adapted to the syntax and functionality of each database. The complete search strings used for each database are provided in Supplementary Table S1. The literature searches were updated as part of the revision process, with the final searches of PubMed, Web of Science Core Collection, and ScienceDirect completed on 8 August 2026.

Records retrieved from the three databases were exported in NBIB or RIS format and merged into a single dataset. Duplicate records were identified by matching DOI information and normalized titles, followed by manual verification. After duplicate removal, titles and abstracts were screened according to the predefined eligibility criteria. Articles considered potentially relevant were retrieved for full-text assessment. The reference lists of eligible articles were also examined for additional relevant publications.

Because several publications originated from the same institutions or research groups, potential overlap between study populations was assessed by comparing authors, study centres, recruitment periods, implant systems, sample sizes, and other available cohort characteristics. Publications with partially overlapping populations were retained when they provided additional outcomes or longer follow-up; however, overlapping patient groups were not considered independent when patient numbers or outcomes were summarized.

2.3. Eligibility Criteria

Studies were eligible for inclusion if they reported clinical outcomes of custom-made acetabular implants used in revision total hip arthroplasty. The population of interest consisted of adult patients undergoing acetabular revision for severe bone loss, including Paprosky type III defects and pelvic discontinuity. Studies were required to include at least four patients and to report at least one clinically relevant outcome, such as implant survival, re-revision, complications, functional outcomes, or radiographic findings. Only full-text articles published in English were considered eligible.

For the purposes of this review, a custom-made acetabular implant was defined as a patient-specific acetabular component individually designed from preoperative CT data and used as the definitive acetabular reconstruction. Custom triflange components and other patient-specific custom acetabular cups or cages meeting this definition were considered eligible. Patient-specific augments used as adjuncts to a conventional acetabular component were not considered definitive custom-made acetabular implants and were therefore excluded from the primary clinical synthesis.

Case reports and studies including fewer than four patients were excluded, as were review articles, editorials, conference abstracts without sufficient clinical data, purely biomechanical or laboratory studies, and studies that did not report outcomes separately for an eligible revision THA population. Studies dealing exclusively with technical, imaging, or implant-positioning aspects without reporting clinical outcomes were not included in the primary systematic synthesis. Such publications were considered separately where relevant to provide technical context in the Discussion.

2.4. Population

The population of interest consisted of adult patients undergoing revision THA for severe acetabular bone loss, most commonly Paprosky type IIIA or IIIB defects, with or without pelvic discontinuity. These complex defects were considered relevant when reconstruction required a patient-specific acetabular component because conventional revision options were insufficient to achieve stable fixation.

2.5. Surgical Intervention

The intervention of interest was reconstruction with a patient-specific custom-made acetabular component used as the definitive acetabular implant in revision THA. Eligible implants were individually designed from preoperative CT data using computer-aided design and manufacturing techniques. These included custom triflange components and other patient-specific acetabular cups or cages designed to achieve fixation in the remaining host bone.

Implant geometry, flange configuration, and screw trajectories could be adapted to the individual defect, available bone stock, planned cup orientation, and intended restoration of the hip center of rotation. Patient-specific augments used only as adjuncts to a conventional acetabular component were not considered part of the intervention of interest.

2.6. Comparators

A comparator was not required for study inclusion, as most eligible studies were non-comparative case series. When available, data from studies comparing custom-made acetabular implants with conventional revision constructs were also extracted. Because comparative studies were limited and differed in patient selection, defect severity, implant design, and reported outcomes, no pooled comparative analysis was planned.

2.7. Outcomes of Interest

The primary outcome of interest was implant survival, defined as retention of the custom-made acetabular component without revision or re-revision at the latest reported follow-up. Kaplan–Meier survival estimates were extracted when available.

Secondary outcomes included re-revision, aseptic loosening, infection, dislocation, mechanical failure, and other implant-related complications. Functional outcomes and radiographic findings were also extracted when reported. Additional variables included follow-up duration, indication for revision, acetabular defect classification, presence of pelvic discontinuity, implant design, and fixation strategy.

2.8. Study Selection and Data Extraction

Following deduplication, two reviewers independently screened the titles and abstracts against the predefined eligibility criteria. Reports considered potentially eligible were subsequently assessed in full text by both reviewers. Disagreements regarding study eligibility were resolved through discussion. Reasons for exclusion at the full-text stage were recorded and used to construct the PRISMA flow diagram.

Data were extracted using a structured template that included study design, study period, sample size, patient characteristics, acetabular defect classification, implant type, follow-up duration, implant survival, re-revision, complications, functional outcomes, and radiographic outcomes when available. Extracted data were cross-checked against the source publications before inclusion in the evidence tables.

Potentially overlapping study populations were identified by comparing author groups, institutions, recruitment periods, implant systems, sample sizes, and reported patient characteristics. Related publications were retained when they provided additional outcomes or longer follow-up, but overlapping patient populations were not treated as independent when summarizing patient numbers or outcomes.

2.9. Quality Assessment and Risk of Bias

The methodological quality of the included non-randomized clinical studies was assessed using the Methodological Index for Non-Randomized Studies (MINORS) [11]. For non-comparative studies, the eight applicable items were scored from 0 to 2 (0 = not reported, 1 = reported but inadequate, and 2 = adequately reported), giving a maximum score of 16. For comparative studies, the four additional MINORS items were also assessed, giving a maximum score of 24.

Quality assessment was restricted to studies included in the primary clinical synthesis. Publications used only to provide technical or radiological context were not subjected to MINORS assessment. Individual study scores are reported in Supplementary Table S2.

2.10. Data Synthesis

Owing to clinical and methodological heterogeneity across the included studies, particularly with respect to defect severity, implant design, follow-up duration, and outcome reporting, a quantitative meta-analysis was not considered appropriate. The findings were therefore synthesized narratively.

Implant survival, re-revision, complications, functional outcomes, and radiographic findings were summarized as reported in the individual studies. Where related publications included partially overlapping patient populations, results were interpreted together and overlapping patient groups were not treated as independent observations.

3. Results

3.1. Study Selection

The database searches identified 506 records: 116 from PubMed, 206 from ScienceDirect, and 184 from Web of Science. After removal of 147 duplicate records, 359 records underwent title and abstract screening, of which 303 were excluded. Fifty-six reports were sought for retrieval, and one could not be retrieved, leaving 55 full-text reports for eligibility assessment. Following full-text assessment, 19 reports were excluded because they did not meet the predefined eligibility criteria. A total of 36 eligible clinical publications were included in the final synthesis. Several publications originated from longitudinally related or partially overlapping patient cohorts and were therefore not considered independent populations when patient numbers or outcomes were summarized. The study-selection process is summarized in the PRISMA flow diagram (Figure 1).

3.2. Study Characteristics

The 36 eligible clinical publications spanned more than two decades and consisted predominantly of retrospective case series and observational cohort studies of custom-made acetabular reconstruction in complex revision THA. Most reports involved patients with severe acetabular bone loss, particularly Paprosky IIIA and IIIB defects, with pelvic discontinuity represented in several series.

Custom triflange acetabular components were the most frequently reported implants, although other patient-specific designs, including more recent 3D-printed components, were also represented. Considerable variation was observed in cohort size, duration of follow-up, implant design, defect severity, and reported clinical outcomes. Follow-up ranged from short-term series to reports extending beyond 10 years.

Several publications originated from the same institutional programmes and represented longitudinal follow-up, subgroup analyses, or partially overlapping patient populations. The 36 eligible publications should not be interpreted as 36 independent patient cohorts, and patient numbers were not summed across all reports. Related publications reporting different follow-up periods or complementary outcomes were retained to preserve relevant longitudinal information while avoiding double-counting when interpreting the results. The principal characteristics and clinical outcomes of the included publications are summarized in

Table 1. Clinical outcomes of custom-made acetabular implants in revision THA.

Author	Year	Journal	Patients (Hips)	Follow-Up	Defect Type	Implant Type	Functional Outcome	Survivorship	Major Complications
Christie † [8]	2001	Clinical Orthopaedics and Related Research	76 patients (78 hips)	Mean 53 months (24–107)	39 combined deficiencies; 39 pelvic discontinuities	Custom-designed triflange cup	33.3 → 82.1	100%	6 recurrent dislocations requiring reoperation (7.8%)
Joshi [12]	2002	Journal of Arthroplasty	27 patients	Mean 58 months (48–72)	Complex major acetabular deficiency	Custom triflanged titanium cementless acetabular implant	All patients improved on modified Merle d’Aubigné–Postel score	2/27 required further revision; ~92.6% unrevised at latest follow-up	6/27 complications (22%)
Dennis [13]	2003	Journal of Arthroplasty	24 cases	Mean 48 months (max 78)	Paprosky 3B massive periacetabular bone loss	Custom triflanged acetabular component	Clinical success reported in 21/24	Clinical success in 21/24 cases (87.5%); formal implant survivorship NR	3 fixation failures; failures associated with hemipelvic dissociation/severe osteopenia
Holt & Dennis [14]	2004	Clinical Orthopaedics and Related Research	26 patients (26 hips)	Mean 54 months (24–85)	Paprosky 3B; AAOS III/IV	Custom triflanged acetabular component	HHS 39 → 78	Clinical success in 23/26 cases (88.5%); 3 component failures	3 failures from loss of ischial fixation
DeBoer † [15]	2007	Journal of Bone and Joint Surgery American Volume	28 patients (30 hips)	Mean 10 years	Pelvic discontinuity	Custom-made porous-coated triflange acetabular prosthesis	41 → 80	100%	5 dislocations; 1 transient sciatic nerve palsy; 1 loose ischial screw
Taunton † [16]	2012	Clinical Orthopaedics and Related Research	57 patients	Mean 65 months (24–215)	Pelvic discontinuity	Custom triflange acetabular component	74.8	95% (free of triflange revision for any reason)	NR
Wind [17]	2013	Orthopedics	19 patients (19 hips)	Mean 31 months (16–59)	Paprosky 3A/3B; AAOS III/IV	Custom triflange acetabular component	HHS 38 → 63; WOMAC 43 → 26	65% considered successful; 2/19 components removed for failure (11%)	3/19 significant complications (16%); 2 component removals for failure
Friedrich § [18]	2014	International Orthopaedics	18 consecutive patients	Mean 30 months (17–62)	Paprosky 3B with pelvic discontinuity	Custom-made acetabular component	HHS 28 ± 12 → 69 ± 13	16/18 radiographically stable (88.9%); formal implant survivorship NR	2 periprosthetic joint infections requiring explantation; 3 recurrent dislocations
Berasi ‡ [19]	2015	Clinical Orthopaedics and Related Research	26 patients (28 hips)	Mean 57 months (28–108)	Paprosky Type IIIB	Custom triflange acetabular component	42 → 65	92.9%	2 septic failures; 1 stem revision; 1 ORIF for periprosthetic femoral fracture; 2 minor complications
Barlow [20]	2016	Journal of Arthroplasty	63 patients	Mean 4.32 years (± 2.94)	Paprosky IIIB defects	Custom triflange acetabular component (CTAC)	WOMAC function: 38.94 → 71.35	86.5%	CTAC failure rate 13.5%
Myncke [21]	2017	Acta Orthopaedica Belgica	20 patient reviews; 22 surgical cases	Mean 25 months	Major acetabular defects	aMace custom-made triflange acetabular component	Mean postoperative HHS 68/100; high satisfaction; mostly no/mild pain	NR	Complications in 8/22 cases; 4 dislocations; technical problems in 8/22
Berend ‡ [22]	2018	Bone & Joint Journal	94 patients (95 hips)	Mean 3.5 years (1–11 years)	Paprosky 2C, 3A, 3B; pelvic discontinuity	Patient-specific triflange acetabular component	46 → 75	94.7%	Overall complications 22%; dislocation 6%; infection 6%; femoral complications 2%
Citak [23]	2018	Hip International	9 patients	NR	Paprosky defects; pelvic discontinuity included	3D-printed patient-specific acetabular component	NR	89%	Overall complication rate 56%; implant-associated complication 11%
Gladnick † [24]	2018	Journal of Arthroplasty	73 patients	Mean 7.5 years (5–12 years)	Paprosky Type IIIB	Custom triflange acetabular component	HOOS-JR median 85 (IQR 73–100)	79.5%	6 revisions for instability (8%); 8 revisions for infection (11%); 12 reoperations without triflange failure (16%)
Kieser [25]	2018	HIP International	46 consecutive; 36 in outcome analysis	Mean 38 months; minimum 24	Paprosky 2A–3B; pelvic dissociation included	Ossis unilateral custom 3D-printed tri-flanged acetabular implant	OHS improved significantly; postoperative WOMAC 98; HHS 79	No revision for aseptic loosening; overall implant survivorship NR	1 deep infection revision; 7 lost to follow-up; 1 recurrent dislocation; 1 early migration later stabilised; 2 concerning for failed osteointegration
Moore ‡ [26]	2018	Orthopedics	37 patients; 35 with ≥10-y follow-up	Minimum 10 years	Large acetabular defects; pelvic discontinuity included	Custom triflange acetabular component	HHS 28 → 90	32/35 unrevised and functioning (91%)	2 components removed for infection; 1 late loosening; 1 ischial screw failure; no dislocations/fractures/nerve injuries
Aprato [27]	2019	International Orthopaedics	8 patients	Early series (patients treated June 2016–August 2018); formal clinical follow-up duration NR	Paprosky 3B	Lima Promade custom-made acetabular device	No standardized patient functional score reported; surgeon questionnaire was favorable	No implant survivorship estimate reported	2/8 postoperative dislocations; 1 superficial infected hematoma treated with drainage and antibiotics
Burastero [28]	2020	International Orthopaedics	19 patients (19 hips)	Mean 42.3 ± 11.8 months	Paprosky IIC, IIIA/IIIB and pelvic discontinuity; septic bone loss	Non-flanged porous titanium custom-made acetabular component	HHS, OHS and VAS improved significantly from preoperative values (p < 0.01)	All implants radiographically osseointegrated; 1 septic failure; no loosening or malposition reported	3/19 patients had complications (15.8%); 1 septic recurrence; 1 recurrent dislocation; 1 positive intraoperative culture; 1 reoperation for recurrent dislocation
Fröschen § [29]	2020	Archives of Orthopaedic and Trauma Surgery	68 patients	Mean 43 months (1–120)	Paprosky IIIA/IIIB with/without pelvic discontinuity	CT-based custom-made acetabular implant	VAS 3.2 → 1.45; HHS 21.1 → 61	75% implant survival at last follow-up; KM 82.7% at 3 y, 77% at 5 y	15 PJI (22%); 7 dislocations (10.2%); 2 aseptic loosenings (2.9%); overall revision 36.7%
Fröschen § [30]	2020	HIP International	4 consecutive patients	At least 2 years for successful cases; variable overall	Paprosky IIIB/AAOS III-IV; failed prior CMAC due to PJI	Second custom-made acetabular component after failed first CMAC	Second-CMAC HHS range 45–58; VAS range 2–4 in successful cases	Treatment success 2/4 (50%)	2/4 s CMACs explanted for recurrent PJI; high reoperation burden
Gruber [31]	2020	BMC Musculoskeletal Disorders	9 patients (16 eligible)	Mean 12.2 months (10–18)	Paprosky 3A (1), 3B (8)	Materialise custom-made acetabular component	OHS 19.8 → 29.4; HHS 50.1 → 68.8	1 re-revision (11.1%)	3 complications (33.3%)
Matar [32]	2020	Journal of Orthopaedics	17 patients (17 hips)	Mean 3.6 years (2–7 years)	Paprosky 3A/3B; pelvic discontinuity in 88%	Custom triflange acetabular component	NR	100%	3 complications (17.6%): hematoma requiring washout; intraoperative ilium fracture; recurrent dislocation
Walter § [33]	2020	Journal of Arthroplasty	54 patients; 58 implants	Mean 56.3 ± 28.7 months (24–120)	Severe acetabular bone defects	21 triflanged + 37 monoflanged custom-made acetabular components	No significant HHS or VAS difference between mono- vs. triflanged groups	Overall survival 72.4% (42/58)	Reasons for revision/explantation: 12 periprosthetic joint infections and 2 aseptic loosenings
Kawalkar [34]	2021	Hip & Pelvis	13 patients; 12 available at follow-up	Mean 50 months	Paprosky 3B; pelvic discontinuity in subset	Triflange patient-matched implant	HHS 41 → 82	11/12 well-fixed at follow-up; no further acetabular reconstruction	1 persistent infection/loosening; 1 dislocation; 1 unrelated death
Scharff-Baauw ¶ [35]	2021	Acta Orthopaedica	49 patients (50 hips)	2 years	Large acetabular defects with/without pelvic discontinuity	Custom-made triflange acetabular component	mOHS 51 → 28.5 (lower score = better); other PROMs improved	0 CTAC re-revisions at 2 y	8 hips with complications; 3 persistent wound leakage, 3 pelvic fractures, 1 dislocation; 5 hips with screw loosening
Sershon [36]	2021	Journal of Arthroplasty	50 patients; 94% with known outcome or ≥2-y follow-up	Minimum 2 years (study period 2000–2018)	Severe acetabular bone loss	Custom triflange acetabular component	49 → 73	98%	14 major complications (28%); dislocation 12%; 1 acute infection; 1 pulmonary thromboembolism; Trendelenburg gait in 46%
Fröschen § [37]	2022	Technology and Health Care	70 patients	Mean 41.9 ± 34.8 months (1.5–120)	Paprosky III with pelvic discontinuity	CT-based custom-made acetabular implant	Functional score not primary focus	53/70 implant survival (75.7%)	17 explantations: 15 PJI, 2 aseptic loosening
Tikhilov [38]	2022	Journal of Arthroplasty	106 revision THAs: 61 custom vs. 45 standard	CMAI: mean 3.1 years (1.0–4.9); SAI: mean 2.8 years (1.0–5.0)	Extensive uncontained acetabular bone loss; pelvic discontinuity subgroup	Custom-made acetabular implant vs. standard acetabular implant	Comparative study; functional outcome was not the principal reported endpoint	Aseptic loosening: 2.4% custom vs. 10.0% standard; pelvic-discontinuity subgroup: 0% vs. 60%	Comparative complication reporting focused primarily on aseptic loosening and re-revision
Winther [39]	2022	Bone & Joint Open	38 patients (39 hips)	Mean 5.1 years (2–11)	Pelvic discontinuity	Custom-made triflange acetabular component	Mean HHS 80.5 (48–96)	5- and 10-year KM implant survival 93.8%; 34/39 stable with healed discontinuity	2 deep-infection revisions; 7 dislocations (5 constrained-liner revisions); 1 DAIR
Alexander ‡ [40]	2023	Journal of Arthroplasty	64 patients (66 hips) implanted; 46 patients (47 hips) available for ≥5-year follow-up	Mean 8 years (5–16 years)	Paprosky 3B and 3C	Custom triflange acetabular component	41 → 64	94.1%	3 triflange revisions due to infection; 5 irrigation and debridement procedures; 1 ORIF; 2 stem revisions for periprosthetic fracture; 1 head revision
Christie † [41]	2023	Journal of Arthroplasty	233 patients (241 hips) implanted; 84 patients (88 hips) included in the ≥10-year/failure analysis	Mean 15.2 years (10–28 years)	Paprosky IIIA, IIIB, IV	Custom triflange acetabular component	NR	89%	43 of 88 hips (49%) required additional surgery; 10 revisions for failure (11.4%)
Faraj ¶ [42]	2023	Bone & Joint Open	18 patients; 22 CTACs	2 years	Paprosky 3B with pelvic discontinuity	Custom-made triflange acetabular component	HOOS, mOHS, EQ-5D and VAS significantly improved; clinically important mOHS improvement in 73%	No mechanical-failure revision; overall revision/reoperation for any reason 3/22 (14%)	6 screw loosening/breakage; 4 fractures; 3 non-healed PD; 1 sciatic paresthesia; 1 recurrent-dislocation revision; 2 DAIR
Meding [43]	2023	Journal of Arthroplasty	41 patients (42 hips) implanted; 39 patients (40 hips) available for ≥5-year follow-up	Mean 10 years (6–13 years)	Paprosky 3A and 3B	Custom triflange acetabular implant	74 (final follow-up)	97.5%	2 deep infections (5%); 4 dislocations in 3 hips (7.5%); 1 radiographically loose implant
Álvarez Valdivielso [44]	2024	Technology and Health Care	23 patients	Mean 67.2 months (0.9–127 months)	Paprosky Type III defects with pelvic discontinuity	3D-printed patient-specific acetabular implant (Mobelife)	NR	87% at 1 year; 78.3% at 10 years	4 revisions total; 3 PJI; 1 aseptic loosening
Jawad [45]	2025	Acta Orthopaedica Belgica	5 patients	Mean 7.8 years (6.3–10.6)	Paprosky 3B	aMace custom-made acetabular implant	Mean HHS 85.6 (70.7–99.5); all patients satisfied	No implant failures reported at latest follow-up	No known adverse events; no radiographic loosening
Mika ‡ [46]	2025	Journal of Arthroplasty	81 patients: 44 constrained liners, 37 standard liners	Median 4.2 years (IQR 2.6–6.7; range 2–15)	Severe acetabular bone loss	Custom triflange acetabular component with constrained vs. standard liner	Functional score not primary outcome	No significant difference in CTAC failure or dislocation-free survival between liner groups	Aseptic CTAC failure: 6.8% constrained vs. 5.4% standard; all-cause CTAC failure: 11.4% vs. 13.5%

Notes: NR = not reported or not available as a precise extractable value. Superscripts identify publications arising from potentially overlapping or longitudinally related cohorts: ^† Christie/Southern Joint Replacement lineage; ^‡ JIS/Lombardi–Berend lineage; ^§ Bonn/Mannheim lineage; ^¶ Sint Maartenskliniek lineage. These are distinct eligible publications; however, because partial or longitudinal cohort overlap could not always be excluded, patient denominators from related reports were not summed as independent cohorts.

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3.3. Indications and Acetabular Defect Characteristics

Most publications evaluated custom-made acetabular reconstruction in patients undergoing complex revision THA for severe acetabular bone loss. Paprosky type IIIA and IIIB defects were frequently represented, and pelvic discontinuity was reported in several series, reflecting the substantial reconstructive complexity of the treated populations [8,14,16,18,22,35,39,42,44]. Other clinical scenarios included recurrent failure following previous acetabular revisions, aseptic loosening, and reconstruction after prior infection or mechanical failure [15,18,28,30,37].

The severity and classification of acetabular defects were not reported uniformly across publications. Although the Paprosky classification was the most commonly used system, some reports described defect morphology using alternative classifications or anatomical descriptions [12,13,17,19,26,31]. Given these differences, the distribution of defect types was summarized descriptively rather than pooled across publications.

3.4. Types of Custom-Made Acetabular Implants

The included publications described a range of custom-made acetabular components designed to address severe bone loss and complex three-dimensional defect morphology. Custom triflange acetabular components were the most frequently reported design, providing patient-specific fixation through the ilium, ischium, and pubis [8,13,14,16]. Other constructs included custom cups, cages, and patient-specific acetabular components produced using computer-aided design and manufacturing techniques [12,18,23,27,28,29,30,31,33,34,35,37,38,44].

Manufacturing strategies evolved substantially over the study period. Earlier reports predominantly described conventionally manufactured or machined custom components, whereas more recent publications focused increasingly on additively manufactured titanium implants with porous or lattice structures intended to facilitate biological fixation [23,25,27,28,29,31,34,35,37,42,44]. Implant geometry, flange configuration, screw trajectories, and porous interfaces were generally planned from preoperative computed tomography data and adapted to the individual defect anatomy [6,7,9,47].

Because implant terminology, manufacturing techniques, and design characteristics varied considerably among publications, direct comparisons between specific implant technologies were not considered appropriate. The findings were therefore interpreted within the broader context of patient-specific acetabular reconstruction rather than as a direct comparison of individual manufacturing platforms.

3.5. Follow-Up and Clinical Outcomes

Follow-up duration varied substantially across the included publications, ranging from short-term postoperative assessment to long-term follow-up exceeding 10 years in several series [8,15,16,24,26,36,39,41,43,45]. This variability, together with differences in cohort composition, implant design, and outcome definitions, limited direct comparison of absolute outcome rates between publications.

Functional outcomes generally improved following custom-made acetabular reconstruction, although the measures used varied across studies [12,14,18,19,20,22,25,28,31,32,34,35,36,39,42]. The Harris Hip Score was among the most frequently reported measures, while other publications used the Oxford Hip Score, WOMAC, HOOS, or HOOS-JR, pain scores, and additional patient-reported outcome measures [18,19,25,28,31,32,34,35,39,42].

Reported implant survivorship varied according to follow-up duration, patient complexity, the definition of failure, and the revision endpoint. Several publications reported survivorship above 90%, including at mid- or longer-term follow-up [15,19,22,26,35,36,39,40,43], whereas lower estimates were observed in some series with substantial infection burden or particularly complex revision populations [28,29,30,37]. Aseptic loosening was relatively uncommon in the included studies, while infection and instability remained important causes of reoperation or implant failure [15,18,20,24,28,29,32,36,39,40,41,42,43].

Because several publications represented longitudinal or partially overlapping patient cohorts, outcome estimates from related reports were interpreted together rather than treated as independent observations. No pooled survivorship, complication rate, or overall patient denominator was calculated.

3.6. Complications and Re-Revision

The type and frequency of postoperative complications varied considerably across the included publications. Infection and instability were among the most consistently reported adverse events and represented important causes of reoperation and implant revision [15,18,20,24,28,29,32,36,39,40,41,42,43]. Periprosthetic joint infection was responsible for several implant failures or explantations, particularly in series involving patients with multiple previous revision procedures or complex reconstructive histories [18,28,29,30,37,39,41].

Dislocation and recurrent instability were reported in several series, although their incidence varied substantially [15,20,24,29,32,36,39,40,41,42,43]. Management ranged from closed or operative treatment to liner exchange or further revision in recurrent cases [20,24,36,39,41,43]. Other reported adverse events included periprosthetic fracture, nerve injury or neurological symptoms, hematoma, wound complications, screw loosening or breakage, and failure of osseointegration [16,18,20,24,28,29,32,35,39,42].

Mechanical failure attributable to aseptic loosening was less commonly reported than infection or instability [15,19,22,24,26,35,36,39,40,41,42,43]. Interpretation of complication and re-revision rates requires caution because definitions of complications, duration of follow-up, and thresholds for reoperation differed across publications. Related reports from overlapping cohorts were not considered independent observations when interpreting the complication profile.

3.7. Technical and Radiological Findings

Technical and radiological investigations provided complementary information on implant design, positioning accuracy, fixation, and postoperative osseointegration [6,7,9]. These publications were considered separately from the primary clinical synthesis because their principal objectives focused on technical or imaging-related outcomes rather than clinical effectiveness.

Technical studies demonstrated the feasibility of CT-based patient-specific planning and manufacturing for complex acetabular reconstruction [6,7]. Patient-specific implant geometry and screw trajectories were designed to optimize fixation within the remaining host bone while facilitating restoration of the intended hip center and component orientation [6,7]. Radiological assessments generally demonstrated satisfactory implant positioning and fixation, although the methods and outcome measures used to evaluate accuracy varied across publications [6,7,9].

Postoperative imaging also provided evidence of stable fixation and bone–implant integration in successfully reconstructed cases [9]. Methodological heterogeneity across the technical and radiological literature precluded quantitative synthesis or meaningful direct comparison between manufacturing or planning technologies. These findings were therefore considered complementary evidence of technical feasibility rather than evidence of clinical superiority.

3.8. Risk of Bias and Study Quality

Methodological quality was assessed using the MINORS instrument [11] for all 36 clinical publications included in the primary clinical synthesis. Among the 34 non-comparative publications, MINORS scores ranged from 6 to 13 out of a maximum of 16 points, with a mean score of 10.2. The two comparative publications scored 15/24 and 14/24, respectively. Because the MINORS scoring framework differs between non-comparative and comparative designs, these scores were not combined into a single overall mean.

The main methodological limitations were the predominance of retrospective designs, limited prospective data collection, absence of prospective sample-size calculations, and incomplete reporting of consecutive patient inclusion or loss to follow-up in some publications. Most reports stated their aims clearly, used clinically relevant endpoints, and provided follow-up periods appropriate to their objectives.

MINORS was applied at the publication level because each eligible report was evaluated according to the methodology and outcomes presented in that publication. Where publications originated from overlapping or longitudinally related cohorts, their methodological scores were interpreted as assessments of the individual reports rather than as evidence from independent patient populations. Individual item scores are presented in Supplementary Table S2.

3.9. Summary of Key Findings

Published clinical studies report favorable outcomes with custom-made acetabular components in patients undergoing complex revision THA for severe acetabular bone loss and pelvic discontinuity. Several studies reported high implant survivorship at mid- to long-term follow-up, and functional outcomes improved in studies reporting standardized clinical measures [19,22,24,26,35,36,39,40,41,42,43,45].

Infection and instability represented the most consistently reported causes of reoperation and implant failure, whereas aseptic loosening was comparatively uncommon [15,20,24,28,29,32,36,39,40,41,42,43]. Considerable heterogeneity was present in patient selection, defect severity, implant design, follow-up duration, and outcome definitions, limiting direct comparison between publications and precluding quantitative pooling.

Technical and radiological studies provided additional information on CT-based patient-specific planning, implant positioning, fixation, and bone–implant integration [6,7,9]. The clinical literature remained dominated by retrospective, non-comparative studies of variable methodological quality. Several publications also represented longitudinal or partially overlapping patient cohorts and were therefore not interpreted as independent observations when synthesizing outcomes.

4. Discussion

This systematic review summarizes the current evidence on patient-specific acetabular reconstruction in revision total hip arthroplasty. The clinical synthesis included 36 eligible publications, most of which were retrospective. Several publications originated from longitudinally related or partially overlapping patient cohorts and were therefore interpreted together rather than as independent patient populations. The included studies reported favorable implant survivorship and improvements in functional outcomes, while aseptic loosening was relatively uncommon despite the complexity of the treated defects, including Paprosky type III defects and pelvic discontinuity [19,22,24,26,35,36,39,40,41,42,43,44,45].

The reported outcomes suggest that patient-specific implants may be a useful reconstructive option when conventional techniques are unlikely to provide adequate mechanical stability [8,14,16,19,22,35,39,42,44]. Several publications reported implant survivorship exceeding 90% at mid- to long-term follow-up, together with improvements in functional outcomes [19,22,26,39,40,43]. Outcomes varied across series, and postoperative complications—particularly infection and instability—remained important causes of reoperation and implant failure [15,20,24,28,29,32,36,39,40,41,42,43]. These findings should be interpreted in the context of substantial differences in patient selection, defect severity, implant design, follow-up duration, and outcome definitions across studies.

4.1. Comparison with Current Literature

Over the past two decades, custom-made acetabular reconstruction has evolved from a salvage option for exceptional cases to an increasingly used strategy for managing severe acetabular bone loss and pelvic discontinuity. Early reports by Christie et al. [8] and DeBoer et al. [15] described the feasibility of custom triflange reconstruction for massive acetabular defects and reported implant retention over extended follow-up. Subsequent publications, including larger series and longer-term follow-up reports, have provided additional clinical data on patient-specific components in highly complex revision settings [22,24,26,35,36,39,40,41,42,43,45].

More recent publications reflect substantial advances in three-dimensional imaging, computer-assisted design, and additive manufacturing, allowing implant geometry, porous interfaces, flange configuration, and screw trajectories to be adapted to individual defect anatomy [6,7,9,23,25,31,34,44,47]. These developments have broadened the reconstructive possibilities for defects in which adequate fixation with conventional components may be difficult to achieve.

Direct comparison between custom-made implants and alternative reconstructive strategies remains limited. Differences in implant design, patient selection, defect severity, previous revision burden, follow-up duration, and outcome definitions make comparisons across series difficult. The predominance of retrospective, non-comparative evidence and the presence of longitudinally related or partially overlapping cohorts limit the strength of comparative conclusions. Custom-made acetabular reconstruction may therefore be considered an option for carefully selected complex revision cases, but the current evidence does not establish superiority over other reconstructive techniques.

4.2. Advantages of Custom-Made Implants

Custom-made acetabular implants offer several potential advantages in the management of severe acetabular bone loss and pelvic discontinuity. Because these implants are designed from patient-specific imaging data, reconstruction can be adapted to individual defect morphology, residual host bone, and the intended restoration of the hip center of rotation [6,7,9]. Custom triflange designs also permit multipoint fixation through the ilium, ischium, and pubis, providing a means of achieving initial mechanical stability when fixation with conventional reconstruction techniques may be difficult [8,14,16,19,22].

Another potential advantage is the opportunity for detailed preoperative planning based on patient-specific three-dimensional anatomy. CT-based modeling enables implant geometry, flange configuration, porous interfaces, and screw trajectories to be planned before surgery, potentially reducing some of the intraoperative uncertainty associated with extensive acetabular defects [6,7,9]. Aseptic loosening was relatively uncommon in the included clinical studies, and several publications reported high implant survivorship, including at mid- to long-term follow-up [19,22,24,26,35,36,39,40,41,42,43,45]. Technical and radiological investigations provided additional information on implant positioning and bone–implant integration [6,7,9]. These theoretical and technical advantages, however, have not been shown to translate into superior clinical outcomes compared with other contemporary reconstructive strategies.

4.3. Technological and Logistical Limitations

Several practical limitations may restrict the broader adoption of custom-made acetabular implants. Their design and manufacturing require high-quality cross-sectional imaging, specialized planning software, close collaboration between surgeons and engineers, and access to dedicated manufacturing capabilities [6,7,9]. These requirements may increase both the complexity and the time needed for preoperative planning and implant production compared with readily available conventional reconstruction options.

Manufacturing lead time may be particularly relevant when revision surgery cannot be substantially delayed or when patients undergo staged treatment for periprosthetic joint infection. Patient-specific reconstruction requires accurate preoperative imaging, appropriate segmentation and implant design, and careful intraoperative reproduction of the planned implant position [6,7]. Changes in bone morphology occurring between preoperative imaging and definitive reconstruction may further affect the correspondence between the planned anatomy and the intraoperative defect.

Technical and radiological investigations provided information on the feasibility and accuracy of patient-specific planning, implant positioning, and fixation [6,7,9]. However, the available evidence does not permit robust conclusions regarding cost-effectiveness, manufacturing efficiency, or accessibility across different healthcare systems. These technological and logistical requirements should therefore be considered when selecting patients and planning custom acetabular reconstruction, particularly in clinical settings where manufacturing resources or engineering support are limited.

4.4. Limitations of Existing Evidence

The methodological quality of the available clinical evidence remains variable. Among the 34 non-comparative publications, MINORS scores ranged from 6 to 13 out of 16, while the two comparative publications scored 15/24 and 14/24 [11]. The evidence base is dominated by retrospective, non-comparative case series, with relatively few prospective investigations and limited comparative data. Selection bias and the concentration of many reports in specialized centers may also make it difficult to generalize these findings, as outcomes achieved by experienced teams may not be directly reproducible across institutions with different case volumes or levels of familiarity with patient-specific reconstruction.

Several methodological limitations were common across the included publications, including small sample sizes, absence of prospective sample-size calculations, incomplete reporting of consecutive patient inclusion, and variable follow-up periods. Differences in defect severity, implant design, surgical technique, outcome definitions, and duration of follow-up further limit direct comparison across reports. Several publications also originated from longitudinally related or partially overlapping patient cohorts. These reports were interpreted together where appropriate to avoid treating overlapping populations as independent evidence. At the review level, potential limitations include restriction to English-language full-text publications, heterogeneity in outcome definitions and reporting across studies, potential publication bias, and the possibility that relevant evidence was not identified despite the systematic search strategy.

These limitations, together with the clinical and methodological heterogeneity of the included populations and interventions, precluded meaningful quantitative pooling. Consequently, the findings of this review should be interpreted as a narrative synthesis of the currently available evidence rather than as pooled estimates of treatment effect. Several clinical series reported favorable implant survivorship and improvements in functional outcomes [19,22,24,26,35,36,39,40,41,42,43,45], although the methodological limitations described above reduce the certainty with which these findings can be generalized. These findings should not, however, be interpreted as evidence of superiority over alternative reconstructive strategies. Larger prospective, multicenter, and comparative studies using standardized outcome definitions and reporting frameworks are required to strengthen the evidence base.

4.5. Clinical Implications for Orthopedic Surgeons

In contemporary orthopedic practice, custom-made acetabular implants may be considered a reconstructive option when conventional techniques are unlikely to provide adequate fixation in the presence of severe acetabular bone loss. Their use may be particularly relevant in patients with Paprosky type IIIA and IIIB defects and in cases of pelvic discontinuity, where achieving stable fixation and restoring hip biomechanics can be especially challenging [8,14,16,18,22,35,39,42,44].

Patient-specific reconstruction requires careful patient selection, high-quality preoperative imaging, accurate implant planning, and close collaboration between the surgical team and implant designers or engineers [6,7,9]. Familiarity with the planned implant orientation, fixation strategy, and surgical technique is also important because these procedures are technically demanding and are frequently performed in patients with substantial bone loss and a history of previous revision surgery [8,16,18,22,39,42].

Reported implant survivorship should be considered alongside the risk of postoperative complications. Infection and instability remain important causes of reoperation and implant failure, whereas aseptic loosening appears to be less frequently reported [15,20,24,28,29,32,36,39,40,41,42,43]. The decision to use custom-made reconstruction should therefore be individualized according to defect morphology, remaining host bone, previous surgical history, infection status, and the feasibility of alternative reconstructive options.

4.6. Future Directions

Future research should prioritize prospective, multicenter studies capable of generating higher-quality comparative evidence. The current evidence base is dominated by retrospective, non-comparative case series, which limits meaningful comparisons between institutions, implant designs, and alternative reconstructive strategies. Greater standardization of outcome reporting, including consistent definitions of implant survivorship, re-revision, complications, radiographic integration, and patient-reported functional outcomes, would improve the comparability of future studies.

Studies with longer follow-up are also needed to establish the durability of custom-made acetabular reconstruction and to identify patient-, defect-, and implant-related factors associated with implant survival and clinical outcomes. Particular attention should be given to the influence of previous revision burden, pelvic discontinuity, infection history, fixation strategy, and implant design on implant failure and re-revision [24,36,37,39,40,41,42,43].

Prospective registries and multicenter collaborations could provide larger and more representative datasets while reducing the limitations associated with small single-center series and overlapping patient populations across publications. Continued advances in imaging, preoperative planning, implant design, and additive manufacturing may further improve the reproducibility and accessibility of patient-specific acetabular reconstruction [6,7,9]. However, whether these advances translate into improved clinical outcomes should be evaluated in standardized, preferably comparative studies.

5. Conclusions

Custom-made acetabular implants represent a valuable reconstructive option for carefully selected patients undergoing revision total hip arthroplasty in the setting of severe acetabular bone loss and pelvic discontinuity. Across the available clinical literature, implant survivorship was favorable in most reported series, functional outcomes generally improved following reconstruction, and aseptic loosening was relatively uncommon. Infection and instability remained important causes of failure and re-revision.

These findings should, however, be interpreted in the context of the limitations of the current evidence. Most available clinical evidence derives from retrospective, non-comparative case series, with considerable heterogeneity in patient selection, defect severity, implant design, follow-up duration, and outcome reporting. Custom-made acetabular reconstruction should therefore be regarded as a valuable option for carefully selected complex revision cases rather than as a reconstruction strategy proven to be superior to conventional alternatives.

Further prospective, multicenter studies with standardized outcome definitions and longer follow-up are needed to better establish long-term implant durability, complication profiles, and the comparative effectiveness of patient-specific acetabular reconstruction.