Contraindications of femoral implants in primary total hip arthroplasty

Abstract

Aims

Litigation related to total hip arthroplasty (THA) is a growing concern. Manufacturer-specified contraindications for femoral implants may influence legal outcomes, particularly when common patient characteristics such as obesity are listed. This study identified manufacturer-listed contraindications for femoral implants used in primary THA and evaluated their medicolegal implications within the frameworks of medical negligence and informed consent law in England and Wales.

Methods

The 11 most commonly used femoral implants were identified from the National Joint Registry of England, Wales, and Northern Ireland. For each implant, manufacturer surgical technique guides were reviewed to extract contraindications, relative contraindications, and warnings. A structured medicolegal analysis was conducted within the frameworks of medical negligence and informed consent law, drawing on landmark case law and peer-reviewed medicolegal scholarship, supplemented by consultation with legal professionals who specialize in orthopaedic device litigation.

Results

Two implants cited obesity or morbid obesity as a contraindication; four reported obesity as a warning. Nine implants listed inadequate bone quality as a contraindication, and two as a relative contraindication. Neuromuscular disease was contraindicated in nine implants, and a relative contraindication in two. Infection was contraindicated in all eleven implants. Vascular deficiency was a contraindication in six implants, and a relative contraindication in two. Deficient musculature was contraindicated in five implants and a relative contraindication in two.

Conclusion

Many manufacturer-listed contraindications correspond to clinical characteristics commonly found in THA patients. These contraindications do not preclude implant use when supported by evidence and sound clinical judgement, but carry significant medicolegal implications under negligence and informed consent law. Once a manufacturer has communicated a contraindication, medicolegal scrutiny may shift to the surgeon’s decision-making under two distinct frameworks, namely the standard of care and informed consent. Surgeons should know their implant-specific contraindications, ensure decisions are evidence-based and documented, and explicitly disclose elevated risks to patients.

Cite this article: Bone Jt Open 2026;7(6):818–824.

Introduction

Total hip arthroplasty (THA) is widely recognized as one of the most prevalent and successful orthopaedic procedures, with approximately 544,000 cases occurring annually in the USA alone.^1,2 While THA substantially improves patients’ quality of life, it is not without the risk of serious complications, including dislocation, periprosthetic joint infection (PJI), and periprosthetic fracture.³

The literature documents a growing proportion of patients undergoing THA with multiple health comorbidities, including osteoporosis and obesity. A majority of patients undergoing total joint replacement have been shown to be either osteoporotic or osteopenic, increasing the risk of periprosthetic fracture.^4,5 Projections indicate that by 2029, over 55% of patients undergoing primary THA will be classified as obese or morbidly obese.⁶ Obesity has been shown to increase the risk of several perioperative complications, including PJI and dislocation.⁷

This rising patient complexity, combined with increased surgical volume, may contribute to a greater risk of litigation. In the USA, orthopaedic surgery already ranks among the most heavily litigated medical fields, with nearly 80% of surgeons encountering at least one lawsuit throughout their careers. Furthermore, arthroplasty surgeons are noted to be the most frequently litigated within the speciality.^8,9 In addition to the direct financial consequences, litigation diverts surgeons’ time and energy from clinical practice.

One under-recognized factor that may influence the outcome of THA litigation is the contraindications specified by manufacturers pertaining to the use of femoral implants. Certain patient characteristics that are becoming increasingly prevalent, including obesity, poor bone quality, and deficient musculature, have been listed as contraindications by certain manufacturers. Additional manufacturer documentation includes relative contraindications and warnings, such as high patient activity levels and manual labour, yet there is little guidance on how these should influence clinical decision-making or medicolegal liability.

To our knowledge, no prior studies have examined manufacturer-listed femoral implant contraindications in primary THA specifically through a medicolegal framework. While prior work has examined the epidemiology of THA litigation^8,9 and the clinical implications of operating on patients with higher-risk characteristics,^4-7 the intersection of implant-specific instructions for use (IFU) contraindications and medicolegal liability in England and Wales has not been previously addressed. Consequently, the potential medicolegal implications of proceeding despite manufacturer-listed contraindications remain unclear, including how such decisions may be evaluated in relation to standard of care, adequacy of informed consent, and attribution of liability if complications occur.

Given the clinical and legal significance of this issue, the objectives of the present study were threefold: first, to systematically identify manufacturer-listed contraindications for the most commonly used femoral implants in primary THA; second, to evaluate the potential medicolegal implications of proceeding despite these contraindications within the frameworks of medical negligence and informed consent law in England and Wales; and third, to outline practical strategies that may help surgeons maintain evidence-based patient care while mitigating litigation risk.

Methods

Femoral implant selection

We identified the 11 most commonly used femoral implants in primary THA as per the National Joint Registry (NJR), which uses data from England, Wales, Northern Ireland, the Isle of Man, and the States of Guernsey. These included: C-Stem, Corail, and Actis from DePuy Synthes (USA); Exeter, Accolade, and Insignia from Stryker (USA); Polar and Anthology from Smith & Nephew (USA); and Avenir, Taperloc, and Echo from Zimmer Biomet (USA).

Implant contraindications

Surgical technique guides for each implant were available through open access on the manufacturer’s website. If unavailable online, guides were acquired by contacting the manufacturer’s representatives, with no objection from any manufacturer for these requests. Each guide was reviewed to extract contraindications, relative contraindications, and warnings. Manufacturers often used different terminology when reporting contraindications. Thus, for clarity, the contraindications, relative contraindications, and warnings in Tables I and III have been condensed. The exact manufacturer descriptions are available in the surgical technique guides as referenced in Table I.

Table I.

Contraindications of the selected femoral implants in primary total hip arthroplasty.

Implant	Contraindications						Instructions for use reference
	Obesity	Inadequate bone stock/quality	Neuromuscular disease	Infection	Vascular deficiency	Loss of musculature
C-Stem DePuy Synthes	No	Yes	Yes	Yes	Yes	Yes	eIFU-090260212 Rev. A
Corail DePuy Synthes	No	Yes	Yes	Yes	Yes	Yes	eIFU-090260220 Rev. A
Actis DePuy Synthes	No	Yes	Yes	Yes	Yes	Yes	eIFU-090260214 Rev. A
Exeter Stryker	No	Yes	Yes	Yes	No	No	QIN 9612-EIFU
Accolade Stryker	Yes	Yes	Yes	Yes	No	No	QIN 4424 Rev. AC
Insignia Stryker	No	Yes	Yes	Yes	No	No	QIN 4441 Rev. AB
Polar Smith & Nephew	No	Yes	Yes	Yes	Yes	No	81098832 Rev. A
Anthology Smith & Nephew	Yes*	Yes	Yes	Yes	Yes	Yes	81120758 Rev. 0
Avenir Zimmer Biomet	No	Yes	Yes	Yes	Yes	Yes	87-6204-952-99 Rev. F
Taperloc Zimmer Biomet	No	No	No	Yes	No	No	01-50-0909 Rev. E
Echo Zimmer Biomet	No	No	No	Yes	No	No	01-50-0950 Rev. S

Each femoral implant and their respective manufacturer are listed in the first column. Pertinent contraindications are included in this Table. The remaining contraindications have been listed in Table II. A ‘Yes’ indicates that the implant manufacturer reported that specific contraindication, while ‘No’ indicates the opposite. Contraindications have been condensed for clarity. The exact manufacturer descriptions are available in the surgical technique guides as referenced in the final column.

^*Morbid obesity.

Table III.

Relative contraindications and warnings for each implant.

Implant	Relative contraindications and warnings
C-Stem DePuy	Obesity or excessive weight, diabetes, manual labour, high levels of activity, falls, active alcohol or drug misuse, other disabilities as applicable, osteoporosis or poor bone stock, metabolic disorders or systemic pharmacological treatments leading to poor bone stock, history of general or local infections, severe deformities leading to impaired fixation or improper positioning of the implant, tumours of the supporting bone structures, allergies or hypersensitivities to implant materials, disabilities of other joints (i.e. knees and ankles).
Corail DePuy	N/A
Actis DePuy	Obesity or excessive weight, diabetes, manual labour, high levels of activity, falls, active alcohol or drug misuse, other disabilities as applicable, osteoporosis or poor bone stock, metabolic disorders or systemic pharmacological treatments leading to poor bone stock, history of general or local infections, severe deformities leading to impaired fixation or improper positioning of the implant, tumours of the supporting bone structures, allergies or hypersensitivities to implant materials, disabilities of other joints (i.e. knees and ankles).
Exeter Stryker	N/A
Accolade Stryker	N/A
Insignia Stryker	Obesity
Polar Smith & Nephew	N/A
Anthology Smith & Nephew	N/A
Avenir Zimmer Biomet	Obesity, high levels of physical activity, sensitivity to metal or allergy to implant material.
Taperloc* Zimmer Biomet	Uncooperative patient or patient with mental disorders who are incapable of following directions, osteoporosis, metabolic disorders, distant foci of infections, vascular insufficiency, muscular atrophy, neuromuscular disease, smoking.
Echo Zimmer Biomet	Uncooperative patient or patient with mental disorders who are incapable of following directions, osteoporosis, metabolic disorders, distant foci of infection, vascular insufficiency, muscular atrophy, neuromuscular disease, smoking.

Relative contraindications and warnings have been condensed for clarity. The exact manufacturer descriptions are available in the surgical technique guides as referenced in Table I.

^*Only Taperloc and Echo used the phrase ‘relative contraindications’, whereas the other implants used ‘warnings’.

N/A, not available.

Medicolegal analysis

To evaluate the medicolegal implications of manufacturer-listed contraindications, we conducted a structured analysis of medical negligence and informed consent law as applicable in England and Wales, the jurisdiction corresponding to the NJR data used to select the implant cohort. Legal principles were derived from primary legal sources, including three landmark cases: Montgomery vs Lanarkshire Health Board (2015) UKSC 11,¹⁰ Bolam vs Friern Hospital Management Committee (1957) 1 WLR 582,¹¹ and Bolitho vs City and Hackney Health Authority (1998) AC 232.¹² These principles were applied systematically to manufacturer-listed contraindications to assess their potential relevance to standard of care and informed consent in the context of THA litigation. Although the analysis is grounded in English and Welsh law, the underlying principles of negligence, standard of care, and informed consent are broadly shared across common-law jurisdictions and are therefore relevant to practising orthopaedic surgeons internationally, though their precise application may differ by jurisdiction. Interpretation of these legal principles in contemporary arthroplasty practice was further informed through consultation with legal professionals who specialize in orthopaedic device litigation.

Results

A total of 11 implants were included in the current study: three from DePuy Synthes (C-Stem, Corail, and Actis); three from Stryker (Exeter, Accolade, and Insignia); two from Smith & Nephew (Polar and Anthology); and three from Zimmer Biomet (Avenir, Taperloc, and Echo).

Two femoral implants cited obesity or morbid obesity as a contraindication to their use, while four additional implants reported obesity as a warning. Regarding inadequate bone stock or quality, nine of the 11 implants listed this as a contraindication, while the remaining two reported it as a relative contraindication. Similarly, neuromuscular disease was listed as a contraindication by nine implants and as a relative contraindication by the remaining two. Infection was listed as a contraindication by all 11 implants. Vascular deficiency was a contraindication for six of the 11 implants, while two additional implants cited it as a relative contraindication. Finally, loss of musculature was listed as a contraindication for five implants and as a relative contraindication by two implants (Tables I and III).

Less frequently reported contraindications included Charcot’s or Paget’s disease (3/11 implants), skeletal immaturity (5/11), pregnancy (2/11), and allergy to implant materials (4/11). Mental disorders that may interfere with activity restriction, or increase the risk of postoperative complications, were listed as a contraindication by four implants (4/11). Local bone tumours or cysts were reported as a contraindication by a single implant (1/11). Two implants (2/11) contraindicated any disease that may endanger the function of the implant, and one implant (1/11) contraindicated any physical condition or activity placing excessive loads on the implant (Table II).

Table II.

Remaining contraindications of the selected femoral implants.

Implant	Contraindications
C-Stem DePuy	Charcot’s or Paget’s disease
Corail DePuy	Charcot’s or Paget’s disease
Actis DePuy	Charcot’s or Paget’s disease
Exeter Stryker	Skeletal immaturity Allergy to implant materials Any mental disorder that would create an unacceptable risk of complications in postoperative care
Accolade Stryker	Skeletal immaturity Any mental disorder that would create an unacceptable risk of complications in postoperative care
Insignia Stryker	Skeletal immaturity Allergy to implant materials Any mental disorder which would create an unacceptable risk of complications in postoperative care
Polar Smith & Nephew	All concomitant diseases that may endanger the function of the implant Allergy to implant materials Pregnancy
Anthology Smith & Nephew	Skeletal immaturity Mental conditions impairing cooperation with postoperative protocols Physical conditions or activities that place extreme loads on implants
Avenir Zimmer Biomet	Skeletal immaturity Any concomitant diseases that jeopardize the functioning or success of the implant Allergy to implant materials Pregnancy Local bone tumour or cysts
Taperloc Zimmer Biomet	N/A
Echo Zimmer Biomet	N/A

N/A, not available.

Discussion

To our knowledge, this is the first study to systematically catalogue manufacturer-listed contraindications for commonly used femoral implants and to integrate this catalogue with a structured analysis of medical negligence and informed consent law in England and Wales, with the aim of informing surgeon decision-making and risk mitigation strategies. The central finding is that many manufacturer-listed contraindications correspond to clinical characteristics that are not rare but rather ubiquitous in contemporary THA practice, including obesity, poor bone quality, and neuromuscular disease. This discordance between manufacturer-listed contraindications and routine clinical practice has received insufficient attention in the orthopaedic literature, and its medicolegal implications remain poorly defined.

The medicolegal implications of proceeding despite manufacturer-listed contraindications should be evaluated within the framework of medical negligence law. In England and Wales, a successful negligence claim requires proof of four elements, namely a duty of care owed to the patient, breach of the applicable standard of care, causation of injury by that breach, and resultant damages. The standard of care has been shaped primarily by Bolam vs Friern Hospital Management Committee (1957) 1 WLR 582, which established that a doctor is not negligent if they act in accordance with a practice accepted as proper by a responsible body of medical professionals. Importantly, manufacturer IFU contraindications do not independently define the legal standard of care; rather, they constitute one factor considered alongside prevailing orthopaedic practice, available clinical evidence, and expert testimony. However, the Bolam standard was subsequently refined in Bolitho vs City and Hackney Health Authority (1998) AC 232, in which the House of Lords held that the body of professional opinion relied upon must be capable of withstanding logical analysis. This is critical in the present context, as a surgeon cannot defend use of an implant against its contraindications simply on the basis that other surgeons do the same. The decision must be grounded in clinical evidence and reasoned judgement applied to the individual patient’s circumstances.

The question of whether liability rests with the manufacturer or the treating surgeon is of fundamental importance. In general, manufacturer liability arises through product liability claims such as defective design, manufacturing defect, or failure to warn, whereas surgeon liability is assessed under medical negligence principles. The Learned Intermediary Doctrine, recognized in the USA and in principle across common-law jurisdictions, provides that a manufacturer satisfies its duty to warn by providing adequate information to the treating physician rather than directly to the patient.¹³ Under this doctrine, once a contraindication has been clearly communicated in the IFU, as is the case for the implants examined in this study, the manufacturer’s warning obligation is discharged and medicolegal scrutiny shifts to the surgeon. If a complication subsequently occurs in a patient for whom the implant was contraindicated, a plaintiff may argue that the surgeon’s decision to proceed constituted a breach of the standard of care. The existence of a contraindication alone does not establish negligence; the plaintiff must demonstrate that proceeding with the surgery fell below the standard of care under Bolam and Bolitho, and that this decision caused or materially contributed to the harm suffered.

In addition to negligence principles governing standard of care, informed consent represents a distinct and frequently litigated basis of liability. The law of informed consent in England and Wales was fundamentally reconstituted by the Supreme Court in Montgomery vs Lanarkshire Health Board (2015) UKSC 11, which replaced the previous physician-centred Bolam test for disclosure with a patient-centered standard. Under Montgomery, a doctor must disclose any risk that a reasonable patient in the claimant’s position would consider material, as well as any risk that the doctor knows this particular patient would consider material. This standard has direct and significant implications for surgeons proceeding despite manufacturer-listed contraindications. Where a manufacturer has identified a patient’s characteristic, such as obesity, as a contraindication or warning, the surgeon possesses specific knowledge of an elevated risk profile. Under Montgomery, a reasonable patient would in most circumstances consider it material to know that the implant carries a manufacturer warning relevant to their specific condition. Accordingly, failure to disclose this during the consent process may give rise to a successful informed consent claim, independent of whether the surgical decision itself breached the standard of care. This is supported by orthopaedic litigation data, with Atrey et al⁹ identifying 78 cases in which an inadequate consent process was the sole basis for successful litigation against English NHS Trusts, with an average settlement of USD $136,178 (approximately £108,000) per case, and many further successful claims in which failure to document recognized complications during the consent process was a contributing factor.⁹

Against this legal framework, the medicolegal implications of each major contraindication category can be more precisely evaluated. The most clinically significant example concerns obesity. Projections indicate that by 2029, more than 55% of primary THA patients will be classified as obese or morbidly obese,⁶ yet 18% of the implants studied list obesity or morbid obesity as a direct contraindication and a further 36% list it as a warning. Although obese patients face a demonstrably higher risk of perioperative complications including infection and dislocation,^7,14 THA is routinely and appropriately performed in this population. Numerous studies have shown that these patients achieve improvements in functional status and quality of life after THA that are comparable with, or in some analyses superior to, those achieved in nonobese patients.^15,16 Under the Bolam and Bolitho standard of care framework, a decision to proceed despite a manufacturer contraindication can be legally defensible where it is supported by robust clinical evidence and applied through reasoned judgement to the individual patient. The medicolegal exposure therefore shifts to the informed consent framework, such that under Montgomery the question becomes not whether surgery was appropriate, but whether the elevated and manufacturer-identified risks were explicitly disclosed to the patient beforehand. In cases where a manufacturer has specifically cited obesity as a contraindication and a surgeon proceeds without disclosing this to the patient, that omission may independently give rise to a successful informed consent claim under Montgomery, regardless of whether the surgical decision itself was defensible under the Bolam standard.

The potential medicolegal significance of contraindications regarding poor bone quality also warrants particular attention given the high prevalence of this characteristic among the arthroplasty population. Nine of the 11 implants studied contraindicate poor bone quality, yet published data demonstrate that osteoporosis or osteopenia affects most patients undergoing total joint replacement.⁴ A surgeon implanting any of these nine devices in a patient with documented poor bone quality is therefore operating against a manufacturer contraindication, potentially without recognizing that this is so. The clinical relevance of bone quality to surgical outcomes is supported by registry data demonstrating that femoral component design and fixation method materially influence periprosthetic fracture risk,¹⁷ and large database analyses have emphasized that periprosthetic fracture is one major factor contributing to early in-hospital morbidity following hip arthroplasty.¹⁸ As with obesity, a decision to proceed in the presence of contraindications regarding poor bone quality may nonetheless be defensible under the Bolam and Bolitho standard of care framework where it is grounded in clinical evidence and applied through individualized judgement. In the event of a complication, however, the existence of this contraindication may attract scrutiny of the implant choice, evaluated against the standard of care frameworks, and furthermore, the adequacy of the consent discussion under Montgomery.

An additional area of concern is the ambiguity with which contraindications are phrased in manufacturer documentation. Terms such as ‘inadequate bone stock or quality’ may encompass a spectrum ranging from severe pathological deficiency, as in osteolysis or bone tumours, to conditions as common as osteopenia, which affects a majority of arthroplasty patients. Likewise, ‘vascular deficiency’ may refer to significant large-vessel flow compromise or to avascular necrosis of the femoral head, a common indication for THA in its own right. This terminological imprecision creates uncertainty for surgeons regarding which patients fall within the scope of a given contraindication and may be exploited in adversarial legal proceedings, where plaintiffs may argue that a documented comorbidity brought the patient within the contraindicated category. Under the Bolam and Bolitho standards, surgeons are required to interpret manufacturer language through the lens of evidence-based medicine and individualized clinical judgement. In cases where a contraindication is ambiguously defined, the responsibility lies with the surgeon to assess its clinical relevance to the specific patient, and to clearly communicate this reasoning to the patient. A well-documented consent discussion that acknowledges the manufacturer warning, and explains the clinical rationale for proceeding, provides protection against both negligence and informed consent claims in the event of subsequent litigation.

Based on this analysis, three practical strategies are recommended for orthopaedic surgeons. First, surgeons should be fully familiar with the manufacturer-listed contraindications, relative contraindications, and warnings for every implant they use, especially where those contraindications appear to conflict with routine clinical practice. A surgeon who is unaware of a manufacturer-listed contraindication can neither make a fully informed decision to proceed nor disclose that contraindication to the patient. Second, where a surgeon elects to proceed despite a listed contraindication, that decision must be grounded in robust and identifiable clinical evidence, applied through expert judgement to the individual patient’s circumstances, and clearly documented in the medical record. This satisfies the Bolitho refinement that such practice withstands logical scrutiny and satisfies the Bolam requirement that the decision is consistent with a practice accepted as proper by a responsible body of medical professionals. Third, in light of Montgomery, surgeons must explicitly discuss manufacturer-listed contraindications and warnings with patients as part of the informed consent process, particularly where the contraindication relates to a characteristic present in that patient. The consent discussion should document the elevated risk, the clinical rationale for proceeding, available alternatives, and the patient’s understanding and acceptance of those risks.

In conclusion, manufacturer-listed contraindications for commonly used femoral implants in primary THA include patient characteristics, notably obesity, poor bone quality, and neuromuscular disease, that are ubiquitous in contemporary arthroplasty practice. Within the frameworks of medical negligence and informed consent law in England and Wales, these contraindications do not preclude implant use when supported by evidence and sound clinical judgement. However, once a manufacturer has adequately communicated a contraindication in the IFU, medicolegal scrutiny may shift to the surgeon’s decision-making under two distinct frameworks, namely whether the decision to proceed was consistent with the standard of care under the Bolam and Bolitho principles, and whether the patient was adequately informed of the elevated and manufacturer-identified risks under the Montgomery standard. Surgeons should be familiar with implant-specific contraindications, ensure their decisions are evidence-based and documented, and disclose relevant contraindications explicitly during the consent process. Adherence to these principles enables surgeons to deliver high-quality, evidence-based care to a complex patient population while substantially reducing their exposure to litigation.

Take home message

- Common manufacturer-listed contraindications for femoral implants, such as obesity and poor bone quality, are ubiquitous among total hip arthroplasty patients.

- Proceeding remains defensible when grounded in clinical evidence and individualized judgement, but shifts medicolegal scrutiny to the surgeon and creates a distinct informed consent obligation.

- Surgeons should know their implant-specific contraindications, document an evidence-based rationale, and explicitly disclose manufacturer-identified risks during consent.

Data Availability

All data generated or analyzed during this study are included in the published article and/or in the supplementary material.