Nail Avulsion: Update with Technical Tips for Successful Outcomes

Abstract

Background

Nail avulsion is a procedure with numerous nuanced iterations and uses within the management of nail diseases, that when performed with intention and skill can imbue the clinician with the ability to manage myriad nail conditions.

Summary

This manuscript serves as a reference for the multiple techniques of nail avulsion as well as clinical indications in various disease states.

Key Messages

Nail avulsion is an often over-simplified procedure with a multitude of uses and variations in technique. This manuscript should serve as an introduction to nail avulsion in the diagnosis and treatment of multiple nail conditions.

Introduction

Nail avulsion is perhaps the most basic, introductory nail procedure, performed in outpatient clinics, urgent care clinics, and emergency rooms, by physicians with training of all backgrounds, podiatrists, non-physician providers, and even students. Despite its widespread use throughout medicine, it is an oft-misrepresented, misguided procedure aimed (erroneously) at curing nail disease, performed inelegantly, leaving patients with complications that are, indeed, unnecessary. In this manuscript, we will tackle avulsion from every direction, focusing on the high yield, specific but limited utility as a treatment cure, as a facet of treatment used in conjunction with other modalities, as a means of exposure for surgery under the plate, and with an emphasis on proper, meticulous technique that will both minimize morbidity and maximize yield of the net procedure.

Techniques for Avulsion

Total Nail Plate Avulsion

Nail plate avulsion can be divided into total versus partial techniques. The former involves removing the entire plate from the nail unit (irrespective of returning it post-surgery), while the latter encompasses the panoply of alternatives [1]. In all cases, the goal should involve removal of the plate with the minimum of bed epithelium attached. The nail bed demonstrates maximum adhesion to the nail plate distally at the onychocorneal (onychodermal) band [2] and loses strength of attachment progressively in the proximal bed. Indeed, the matrix-plate connection is extremely tenuous.

Distal Total Plate Avulsion

Traditional total plate avulsion is termed distal when the plate is undermined starting distally and moving proximally. A few instruments have been used historically for this purpose, including nail elevators, spatulas, hemostats, or scalpel blades. Regardless of the instrument, the motion should be primarily distal-to-proximal rather than sweeping side-to-side, to minimize shearing the longitudinally running nail bed rete ridges. Once the distal seal is breached, the practitioner should advance the instrument slowly and with an upward pressure on the plate to diminish damage to the bed. The dorsal/proximal attachments are also undermined, breaking the seal of the cuticle and lateral nail grooves. Once these steps have been performed, a hemostat, needle driver, or specialty instrument can grasp the plate with a generous bite at the distal/lateral edge and complete the avulsion with a twisting motion. When performed correctly, the plate is removed with minimal force, the bed shows preserved longitudinal rete ridges, and the plate undersurface is clean and translucent. If the plate is to be returned to anatomic position post-procedure, it can be soaked in chlorhexidine and rinsed with saline prior to replacement to decrease risk of post-operative contamination.

The authors propose that in select circumstances, undermining the ventral plate with narrow, curved scalpel blade (15, 15c, Beaver) is preferable to blunt undermining as described above. This technique preserves the maximum amount of nail bed epithelium. Doing so requires surgical finesse and meticulous attention to detail, delicately penetrating the onychocorneal band and precisely teasing away the plate-bed connections with the tip of the blade (Fig. 1). Once the blade tip reaches the proximal bed, we suggest changing to a blunt instrument as there is very little resistance and the risk of shearing nail bed epithelium is low. The authors suggest incorporating this technique only once others have been mastered and when the goal of the procedure involves a maximally preserved nail bed epithelium (e.g., biopsy of suspected onychopapilloma).

Fig. 1.

A 15 blade is used to delicately tease apart the ventral plate and nail bed. Care is required to avoid cutting into the bed, rather staying above the bed and below the plate.

Proximal Total Plate Avulsion

In contrast, a proximal total plate avulsion is in many ways the reverse of the distal technique and is best performed with a nail elevator or spatula. It involves undermining under the proximal nail fold first, lysing the cuticle and eponychial connections in order to reach the cul de sac. This is experienced as a resistant barrier after undermining. The instrument is then rotated almost 180° proximally so that the dull tip of the instrument finds a place under the proximal free edge of the nail plate. At this point, the proximal plate-matrix connection is undermined and the instrument advanced proximal to distal to complete the disconnection of the plate and bed (Fig. 2). This type of avulsion is useful in cases with prominent nail bed swelling and/or hyperkeratosis, which makes distal undermining more challenging.

Fig. 2.

Proximal total plate avulsion. The elevator is inserted under the proximal nail fold, advanced proximally and turned under the proximal plate.

Partial Nail Plate Avulsions

There are numerous partial nail plate avulsions; however, they can be divided into five general categories: trap door avulsion, lateral plate curl, partial proximal plate avulsion, strip avulsion, or window avulsion. These will be addressed individually, with logical clinical indications for each found in Table 1. When returning the nail plate to its native position post-procedure, it can be set with suture or cyanoacrylate adhesive [3, 4]. Specifically, the authors use rapidly absorbable polyglactin 910 suture (5–0 on a P3 needle) in most cases.

Table 1.

Avulsion techniques and common indications

Avulsion technique		Clinical indications
Complete nail plate avulsion	Treatment of retronychia to facilitate total matricectomy	Retronychia
		Terminal malalignment
Trap door avulsion	Visualization of the entire nail bed and distal matrix to diagnose and treat distal matrix and bed pathology	Nail bed tumors
		Longitudinal erythronychia
Lateral plate curl	Visualization of a portion of the nail bed and distal matrix to diagnose and treat laterally based distal matrix and bed pathology	Combination of nail matrix and bed pathology
		Glomus tumors
		Longitudinal melanonychia
		Longitudinal leukonychia
Partial proximal plate avulsion	Visualization of the matrix to diagnose and treat matrix pathology	Longitudinal melanonychia
		Pathology limited to matrix or submatrix
Strip avulsion	Exposure of strip of nail bed and distal matrix	Lateral matrix horn matricectomy
		Onychomycosis (select cases)
Window avulsion	Exposure of a window of nail bed or distal matrix	Subungual hematoma or abscess, proximal plate leukonychia alternative to trephination

Trap Door Avulsion

Originally described by de Berker, the trap door avulsion exposes the hyponychium, entire length of the nail bed, and the distal and intermediate matrix. The proximal matrix and eponychium are not exposed, and, as such, this technique is not recommended in surgery for longitudinal melanonychia, when intraoperative evaluation of these structures is indicated. The trap door avulsion can be performed on the entire plate or only portion of the plate (termed hemi-trap door avulsion), depending on the location and width of the lesion. This technique involves undermining only the ventral plate; the dorsal plate/cuticle connection is not touched, thus minimizing risks of postoperative paronychia. The underside of the plate is undermined in an identical fashion as in the total distal plate avulsion, using a spatula/elevator, hemostat, or occasionally a scalpel blade as noted above. The nail plate is then grasped with a clamp and lifted from the bed, simulating a trap door (Fig. 3). For more exposure, tangential incisions can be made in the proximal nail fold and the plate and proximal nail fold can be reflected more proximally. The surgery is then performed. The nail plate is generally returned to anatomic position after the procedure and set with either suture or tissue glue.

Fig. 3.

Three images of variations of trap door avulsions, including a hemi-trap door avulsion (bottom right).

Lateral Plate Curl

The lateral plate curl avulsion is a versatile technique that exposes the entire length of the nail unit and can be expanded to expose nearly the entire unit. It is ideal for surgeries requiring wide exposure when the nail will be returned to anatomic position postoperatively. First, the dorsal cuticle/plate connection is undermined with a spatula/elevator or hemostat. Then a hemostat is introduced into the lateral nail sulcus and clamped over the length of the nail plate. The hemostat is then twisted, rolling the nail plate in a motion likened to opening a roller shade (Fig. 4). The degree of undermining should match the exposure required. The surgery is then performed, and the nail plate subsequently uncurled until it fits back in its native position and is set with sutures. In certain circumstances, the uncurled plate may need to be trimmed in order to be returned to anatomic position elegantly.

Fig. 4.

A lateral plate curl avulsion accessing the entire length of the nail unit.

Partial Proximal Plate Avulsion

This workhorse technique is suitable for most cases of longitudinal melanonychia biopsy, although it can be used whenever the pathology is limited to the matrix or submatrix. It differs in many ways from the prior methods and requires a nail splitter. First, the dorsal cuticle/plate connection is undermined with a spatula/elevator or hemostat. A nail splitter (preferably English anvil-action) is inserted into the lateral sulcus, perpendicular to the longitudinal axis of the plate. The anvil base is shimmied under the lateral plate edge and the plate is cut transversely, anywhere between 50% and 90% across the nail plate, depending on the amount of matrix exposure required. The exposed lateral side of the now undermined proximal plate is grasped with a hemostat and reflected away from the underlying tissue, in a motion likened to opening a can of sardines. This technique is paired with tangential incisions in the proximal nail fold on either side of the area of interest, allowing for reflection of the proximal nail fold and exposure of the entire matrix. The proximal nail fold must be held away from the matrix, either with skin hook, forceps, or suture for traction (Fig. 5). Surgery is performed. Immediately post-surgery, the proximal nail fold and nail plate are returned to native position and set with either sutures or tissue adhesive.

Fig. 5.

Three images of partial proximal plate avulsions for intraoperative exploration before biopsy of longitudinal melanonychia.

Strip Avulsion (Also Termed Longitudinal Partial Plate Avulsion)

Originally described as a longitudinal partial plate avulsion, the authors now prefer the term “strip” avulsion for brevity and to avoid confusion with similarly labeled partial proximal plate avulsion. The strip avulsion is an important precursor to chemical matricectomy for ingrown nails, as well as a versatile technique for surgeries involving the lateral nail unit, in particular when the surgeon wishes to send the plate for laboratory processing along with underlying tissue. One may analogize this method as the longitudinal equivalent of the transversely oriented partial proximal plate avulsion. As such, an English anvil-action nail splitter is inserted anvil side down distally under the free edge of the plate and advanced while cutting distal to proximal, carefully moving under (and not involving) the proximal nail fold, until the entire plate is incised. Both dorsal/proximal and ventral plate surfaces are undermined as detailed above. This nail strip can then be atraumatically removed with a hemostat (Fig. 6). Surgery is performed. This wound is left open after chemical matricectomy. In other surgeries, the wound is either left open, nail plate replaced, or faux nail inserted (see below).

Fig. 6.

A strip avulsion is cut with an English anvil-action nail splitter (left), grasped and removed with a hemostat (middle) prior to phenolization for pincer nail deformity.

Window Plate Avulsion

Window plate avulsion describes a range of partial avulsions that are generally small and targeted to expose a limited area of nail bed. In cases when one suspects a neoplasm, it does not provide adequate surgical exposure for proper exploration. Ideal indications for window avulsions are for inspection of subungual tumor, hematoma, or abscess, to sample proximal plate leukonychia, or when trephination is inadequate or contraindicated. The procedure is performed with a scalpel blade and spatula to cut and undermine a window of nail plate, either on 3 sides and flipped open in a motion likened to a submarine door opening or as a distal segment of nail plate (Fig. 7). Alternatively, a punch instrument appropriately sized to the underlying area of interest can be used to create a window in the plate, removed like a manhole covering.

Fig. 7.

Distal window plate avulsion revealing a nail bed squamous cell carcinoma.

Avulsion for Therapy

Almost daily in a tertiary nail clinic, a patient is referred expressly for a complete nail plate avulsion, yet only a few times a year is a total nail avulsion the therapeutic treatment of choice. Of the myriad nail maladies, only one can count a complete nail plate avulsion as the most effective therapeutic treatment: retronychia.

Retronychia is defined as proximal ingrowing of the nail in the setting of incomplete onychomadesis. The resultant foreign body reaction within the proximal nail fold prohibits expulsion of the offending plate prior to growth of a new underlying nail plate. Frequently multiple nail plates stack underneath the proximal nail fold leading to xanthonychia and a painful, oftentimes purulent, paronychia with or without granulation tissue [5].

In milder cases, high potency topical or intralesional steroids can be used to decrease inflammation and coax the offending plate(s) to expel distally; however, in many instances the inflammatory response is too robust and the burden of embedded nail plate(s) too great for successful conservative treatment [6, 7].

Prior to surgical treatment, the nail plate should be inspected to evaluate for degree of onycholysis. Some patients will have entire plates that are onycholytic and others where the distal plate is still adherent. In those latter patients, it is important to try to preserve the distal plate to prevent post-operative nail bed contraction as discussed further below.

After complete anesthesia is obtained, a nail elevator is used to disrupt the cuticle seal of the proximal nail fold and to loosen the adhesions of the lateral plate and lateral nail folds. The elevator is then inserted further beneath the proximal nail fold and used as a lever to elevate the proximal most plate. This process is identical to a proximal total plate avulsion as detailed previously. The elevator is alternated between the distal and the proximal edges of the offending plate, gently twisted and rocked until the plate(s) can be gripped with a curved hemostat and coaxed free of the nail folds. In those cases where the distal plate is to be preserved, an English anvil nail splitter is advanced across the midpoint of the nail plate transversely in order to split the nail at the inflexion point between onycholytic proximal plate and attached distal plate. The distal plate is stabilized with the non-dominant hand and a hemostat used as above to grip the proximal plate(s) and remove them from beneath the nail fold (Fig. 8). The removal of the nail plate(s) typically leads to rapid resolution of inflammation, allowing the new nail plate to grow in without incident. A recent report also demonstrates the utility of CO₂ laser to assist in this proximal plate avulsion [8].

Fig. 8.

Proximal plate avulsion in the setting of retronychia. The double nail is visualized in the avulsed proximal nail specimen.

Avulsion as a Part of Therapy (Pincer, Ectopic, Ingrown, Malalignment, Onychomycosis)

Nail avulsion has a role as one step of many in the treatment of multiple diseases in which all or a part of the nail plate is growing in such a way as to cause recurrent symptoms. The most common of these are ingrowing nails, pincer nails, end stage malalignment of the great toenails, and onychomycosis.

Ingrowing toenails affect patients of all age-groups and can significantly impact quality of life. The most common form of ingrowing is distal and lateral wherein the nail plate is cut at an oblique angle distally. Due to the counterpressure from walking, the distal and lateral pulp herniate caudally leading to embedding of the plate into the lateral nail fold as it grows. The embedded plate leads to an inflammatory response and resultant soft tissue edema, further exacerbating the ingrowing. In those patients with infrequent episodic disease, conservative management aimed at separating the plate from adjacent skin by way of anchor taping [9] or cotton casting [10], with or without the use of topical or intralesional steroids, can be effective at mitigating symptoms and preventing recurrence. When conservative management fails or patients suffer from repeated symptomatic ingrowing, surgical treatment becomes the treatment of choice, with lateral plate strip avulsion followed by chemical matricectomy emerging as the gold standard [11, 12]. Alternatively, the soft tissue itself may be excised, leaving the plate and matrix intact. As these procedures do not involve avulsion, further discussion of them is unnecessary in this context.

When performing a lateral strip avulsion in conjunction with chemical matricectomy for the treatment of an ingrowing nail, it is important to make the strip (and thus exposure of matrix to be ablated) as narrow as possible to prevent undue narrowing of the nail plate that could be cosmetically displeasing to the patient and to prevent iatrogenic malalignment of the remaining toenail. Care must also be taken to remove any nail plate remnants embedded in the lateral horn and lateral nail folds that have resulted from improper nail cutting and contribute to ongoing inflammation. The chemical agent is then applied to the lateral matrix to ablate this germinative epithelium and prevent growth of the lateral plate in the location of chronic ingrowing. There are many methods for chemical cautery that are beyond the scope of this manuscript.

Pincer nails are caused by an increased transverse curvature of the nail plate. Etiologies are multifactorial, with the most common cause related to arthritic changes of the distal interphalangeal joint. In many patients, the disease state is symptomatic as well as cosmetically bothersome and may present as ingrowing nails. In those patients where symptomatic relief is the primary goal of treatment, a strip avulsion of the offending lateral plate edges can be performed followed by selected chemical cautery of the matrix horns (Fig. 6). The result of this procedure is a narrowed but flattened nail plate with resolution of the lateral nail plate embedding. This can be performed in isolation, or in conjunction with removal of a dorsal traction osteophyte and nail bed widening surgery [13].

Malalignment of the great toenails can be hereditary, acquired, or iatrogenic. Regardless of the etiology, the malaligned plate has poor adherence to the nail bed and with years of recurrent and persistent onycholysis due to microtrauma can lead to a plate that is thickened, miniaturized, triangular, and often painful. In these patients, the distorted nail plate often has limited functionality and proves to be more cumbersome than useful (Fig. 2). As a therapy for what the authors term “end stage malalignment,” total plate avulsion followed by complete chemical matricectomy can be performed for symptomatic relief and definitive treatment.

Onychomycosis is the one of the most common nail complaints encountered in dermatology and can pose significant therapeutic challenges. While fungal debulking, in particular removal of dermatophytomas, is a logical step in the treatment of onychomycosis, data suggesting its routine use are lacking. Avulsion, whether partial or complete, should be used judiciously to prevent post-procedural complications such as pain, paronychias, miniaturization of the nail bed, and distal embedding [14]. Avulsion in combination with topical and/or oral treatments should be reserved for select refractory patients as data showing its efficacy are not established [15].

Avulsion for Exposure

Successful nail surgery depends on multiple codependent factors. Key among them is adequate exposure of the target area of interest in the nail apparatus, in order to visualize and access those sites with maximal efficiency and minimal morbidity. For most nail procedures, this is accomplished with partial nail plate avulsion. [1] While a total nail plate avulsion will effectively expose the entire nail apparatus, doing so carries several limitations: more trauma to the tissue, lysis of the cuticle/proximal nail fold/lateral nail fold seal promoting acute and chronic paronychia postoperatively, contraction of the nail bed due to loss of the rigid plate during months-years of plate regrowth. For certain conditions, however, there is no good alternative to total plate avulsion to provide access – this is especially true with large subungual tumors and with specific primary matrix fibroepithelial tumors such as onychomatricomas. Indeed, with this particular tumor, avulsion of the involved plate (this can be a hemi-plate avulsion for laterally located tumors) is a requirement for visualization of the filiform primary matrix neoplasm that will allow precise extirpation. In other instances of subungual tumors, either a wedge/excisional biopsy (taken with the plate attached preferably when invasive melanoma is suspected to capture all prognostic staging information) or partial plate avulsions are preferable.

Notwithstanding these exceptions, it remains true that partial nail plate avulsions provide the most elegant and targeted approach to many if not most nail surgeries. These have been detailed in a prior publication but deserve mention again, with certain updates gleaned from years of experience. [1] (Table 1) Longitudinal melanonychia, for instance, is a primary matrix neoplasm best approached with either a partial proximal plate avulsion (Fig. 6) or lateral plate curl (Fig. 4). Both expose the entire length of the matrix as well as the eponychium, so that an excisional tangential biopsy can be performed.

Longitudinal erythronychia and leukonychia, distinct but often overlapping conditions, tend to reflect either a distal matrix and bed pathologic process (such as onychopapilloma or Bowen’s disease) or a submatrix condition (such as a glomus tumor or caliber persistent artery). Exposure here does not usually require access to the proximal most matrix and eponychium, and hence a trap door or hemi-trap door avulsion (Fig. 3) is preferred.

The key to this type of surgical decision-making lies in the clinical evaluation of the patient preoperatively, knowledge of the underlying disease process, and accurate determination of the scope of surgery necessary for the appropriate diagnostic surgical intervention. Table 1 provided will help guide the nail surgeon; however, this does not replace detailed history, physical and dermoscopic examination, as well as understanding of nail anatomy and disease presentations.

In all instances, partial nail plate avulsions lend themselves to returning the plate to anatomic position when the matrix biopsy is completed. However, when the nail plate contains important diagnostic information, that portion of nail plate should be sampled for histopathologic processing and/or mycologic/bacterial evaluation. Most nail surgeries, though, do not require processing of the plate when targeting nail matrix, bed, or folds, and the plate can be returned to its original position when finished the underlying surgery. The plate acts as a splint, a biologic dressing, and even split thickness graft of any adherent onychocytes on the ventral surface. In most instances, this returned plate eventually sheds. Patients must be counseled on this prospect and educated on how to keep it trimmed short and watch for a “new nail” growing in behind it. The authors also routinely have patients review pictures of the normal healing process after partial proximal avulsion [16]. We have found that using an adhesive (“steri-“) strip to keep the plate in place during healing will minimize discomfort and allow the returned plate to stay in position as long as possible. And although it has not been studied with a specific endpoint, it does appear that returning the plate confers less pain during recovery.

Complications and Avoidance of Complications

As detailed above, complete nail plate avulsions should be reserved for specific circumstances to minimize complications and optimize post-operative recovery. Complications can be anticipated based upon the anatomy of the nail unit and the part of the plate that is removed.

When proximal plate is removed, there is undoubtedly some amount of microtrauma sustained by the undersurface of the proximal nail fold and the underlying nail matrix leading to exposed dermis. This can be intentional, as in the removal of a specimen for a matrix biopsy, or unintentional as in the inevitable abrasion of the underside of the proximal nail fold from the insertion of a nail elevator or other surgical instrument necessary to facilitate plate avulsion. If these areas of microtrauma are allowed to adhere in the post-operative period, this can lead to fusion of the undersurface of the proximal nail fold and the matrix and resultant dorsal pterygium.

To mitigate this risk, these authors recommend either returning the nail plate to anatomic position following the procedure or the use of a soft faux nail to splint the surgical site and prevent adherence of the underside of the nail fold to the exposed matrix [17] (Fig. 9). The decision as to whether to return the nail plate to anatomic position typically depends on if the nail plate is being sent for histologic analysis. These authors endorse the use of a pediatric nasopharyngeal tube as an agent with which to craft a faux nail. These are sterile flexible instruments that can be trimmed to fit the defect and sutured into place. The faux nail is typically removed at 2 weeks to prevent a foreign body inflammatory response. The vulnerable surfaces should be re-epithelialized at that point, mitigating the risk of pterygium.

Fig. 9.

A faux nail (splint) is sutured into place after a lateral strip avulsion.

Removal of the lateral plate in the form of a strip avulsion in conjunction with chemical cautery or excision of the lateral matrix can lead to undue asymmetric narrowing of the nail unit. Depending on the specific anatomy of the patient, this narrowing can contribute to, or create, malalignment of the nail with respect to the long axis of the distal phalanx, which can be both cosmetically distressing and symptomatic. Lateral strip avulsions should be kept as narrow as possible and perpendicular to the transverse axis of the nail unit to decrease this risk.

A Special Note for Toenails

Nail plate avulsion on the toenails as compared to the fingernails carries greater complications due to the inherent difficulty in foot/toe immobilization and the relatively slow growth rate of toenails. The primary functional role of the toenail plate is providing counterpressure to the ventral pulp when walking. When the nail plate is removed, the mobile pulp is pushed upward with the repeated force of ambulation. Without the stabilizing force of the nail plate, this distal toe soft tissue can become hypertrophic and over time encroach upon the nail bed, predisposing to a faulty nail wall and distal embedding of the regrowing nail plate [18]. In addition, one can see metaplasia of the distal nail bed with the development of dermatoglyphs that prevent future adherence of the distal plate to the distal bed [19]. This disappearing nail bed sign is an irreversible sequela of repeated onycholysis or iatrogenic avulsion that leads to a miniaturized nail bed and ultimately a miniaturized nail plate.

An additional consequence of nail plate avulsion of the toenail is a chronic paronychia due to disruption of the proximal nail fold-nail plate connection. Any partial plate avulsion that is returned to anatomic position will be repeatedly traumatized during ambulation, leading to nail fold inflammation and chronic paronychia. It may be that the main utility of partial nail plate avulsions, then, is in the surgery of fingernails given this predictable challenge postoperatively.

Conclusion

Nail avulsion in some form remains a mainstay of nail surgery, either exclusively (as in treatment of retronychia) or in conjunction with other techniques in the diagnosis and/or treatment of multiple nail conditions. Thorough knowledge of nail anatomy and diseases will direct the appropriate use of avulsion in the management of these disorders.

Conflict of Interest Statement

The authors have no conflicts of interest to declare.

Funding Sources

No funding was received in support of this manuscript.

Author Contributions

Nathaniel Jellinek: the author confirms substantial and equal responsibility for the following: study conception and design, data collection, analysis, manuscript preparation, reviewing it critically for important intellectual content, and final approval of the version to be published. The author is in agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Julia Baltz: the author confirms substantial and equal responsibility for the following: study conception and design, data collection, analysis, manuscript preparation, reviewing it critically for important intellectual content, and final approval of the version to be published. The author is in agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Funding Statement

No funding was received in support of this manuscript.