Prognostic Scoring Systems in Ossiculoplasty: A Comprehensive Review and Introduction of a Novel Predictive Index

Abstract

Ossiculoplasty remains a challenging surgical procedure, with outcomes heavily influenced by diverse anatomical and pathological factors. Over the decades, numerous scoring systems have been developed to predict the prognosis of ossiculoplasty, each emphasizing different variables such as ossicular status, middle ear environment, and surgical history. This paper provides a comprehensive review of the evolution of prognostic scoring systems, including Austin’s original ossicular classification, Bellucci’s otorrhea staging, the Middle Ear Risk Index (MERI), the Ossiculoplasty Outcome Parameter Staging (OOPS), and the recently introduced Ear Environment Risk (EER) scale. While these systems have significantly contributed to preoperative assessment, each presents notable limitations in encompassing all variables affecting surgical success. Therefore, the aim of this paper is to provide a review of the ossiculoplasty prognostic scores and show the benefits, innovations and gaps associated with each. To address these gaps, a novel, modified scoring system is proposed, incorporating previously overlooked but clinically significant factors such as tympanic membrane status, type of tympanoplasty, ossicular replacement material, CT scan findings, and the presence of complicated ear conditions. By synthesizing elements from historical scores with updated clinical insights, the proposed system aims to provide a more holistic and predictive framework for preoperative evaluation. Future multicenter studies are encouraged to validate the efficacy and prognostic power of this new scoring system, with the goal of improving surgical planning and patient counseling in ossiculoplasty.

1. Background

The stapes, together with the malleus and incus, form the three bones of the ossicles (Young and Ng, 2023). These ossicles are within the middle ear, and they form a moving chain into the oval window from the tympanic membrane (Gaillard et al., 2023). Any impairment in sound transmission from the external auditory canal to the cochlea of the inner ear is referred to as conductive hearing loss (Young and Ng, 2023). Ossicular disorders occur due to disorders such as cholesteatoma, chronic infection, chronic inflammation, neoplasia, and congenital abnormalities or malformation (Kamrava and Roehm, 2017). The fixation of the ossicles generally arises as a result of scar bands following either chronic otitis media or ossicular tympanosclerosis following the healing of a perforation or due to ankylosis of the malleus head, which occurs idiopathically (Gleeson and Clarke, 2008; Arasan, 2017). To tackle this issue, ossiculoplasty is performed. Ossiculoplasty is a surgical procedure that is performed to restore the continuity of the ossicular chain, and thus the ability of sound conduction in the middle ear, through interposition of one of the many types of devices or autologous modeled incus (Berenholz et al., 2012). In ossiculoplasty, surgeons used to be divided into those that preferred natural prostheses and autografts for reconstruction and those that preferred homografts (Javia and Ruckenstein, 2006). With recent advancements, Malafronte et al. (2024) has now even developed semisynthetic prostheses. Since autografts may not always be available, their popularity has decreased, and this was further proven by Goldenberg et al., which showed that 70% of otologists prefer synthetic material (Wehrs, 1985). In contrast to this, the authors believe that despite not always being available, autologous ossicles are the gold standard for the reconstruction of the sound transmitter mechanism. We recommend a two-stage surgery wherein, in the first stage of tympanoplasty, the residual autologous ossicle is collected and stored in 95° alcohol. Then, in the second stage, after 8 to 10 months, the residual autologous ossicles are used to remodel and reconstruct the ossicular chain. This is also supported by Lüers et al. (2010). Synthetic ossicular prostheses have three types, which are partial ossicular replacement prosthesis (PORP), total ossicular replacement prosthesis (TORP), and incus replacement prosthesis (Dumont et al., 2019). Each of these different types has different indications, complications, and prognoses. Among the common complications of prosthesis is dislocation of the device. To tackle this, Malafronte et al. (2024) have developed a semisynthetic TORP that has shown promising results in cases of both present and absent stapes suprastructure. The prognosis of surgery also depends on challenges that the operating surgeon is prone to face, such as adhesive otitis media, eustachian tube dysfunction, and middle ear fibrosis (Berenholz et al., 2012).

Other variables that impact the outcome of ossiculoplasty are the presence of otorrhea, atelectasis, preexisting status of the ossicles, mucosal health, and revision surgery, among others (Austin, 1985; Bellucci, 1989; Black, 1992). With this being said, the fate and success of an ossiculoplasty are difficult to assess preoperatively by the otologists, as there are limited methods to statistically determine the severity of clinical features. For these reasons, many surgeons have developed different scores in an attempt to predict the outcome of ossiculoplasty. In this study, a comprehensive literature review is conducted to find and summarize the development of different ossiculoplasty scoring systems across time, from Austin’s original ossicular chain classification to the latest Ear Environment Risk (EER) scale by Michael B. Gluth et al. (2025). Furthermore, the first author proposes a new scoring system, with evidence from the literature, emphasizing other variables that are not considered in the previous scores.

2. Review of the Literature to Explain the Evolution of the Scores

The following keywords were used to search the literature: (Ossiculoplasty OR Tympanoplasty AND Outcome OR Result OR Staging OR Prognosis OR "Prognostic factors"). Figure 1 shows the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow chart that highlights how the literature review was conducted.

Figure 1.

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow chart that highlights how the literature review was conducted.

These are the scoring systems in chronological order:

2.1. Austin’s (1985) classification of the ossicular chain

The original classification was proposed by Austin in 1971, where he segregated the ossicular status into 4 different groups. Group A comprised patients with both their malleus and stapes intact; however, these patients had their long process of incus eroded. Furthermore, Group B were patients with only their malleus present and their stapes completely absent. In contrast to group B, patients in group C had their stapes present but with absent malleus. Finally, patients who had both their malleus and stapes suprastructure absent made up Group D. This original classification of the ossicular status shed light on the significant impact of preoperative ossicular status on the postoperative outcome of ossiculoplasty, serving as a breakthrough for all other ossiculoplasty scores that attempt to preoperatively predict the outcome based on the preoperative condition of the ear.

- Group A—Malleus and stapes present, with erosion of the long process of incus

- Group B—Malleus present but absent stapes (footplate of stapes present)

- Group C—Stapes present but absent malleus

- Group D—Malleus and stapes suprastructure absent

This original classification of the ossicular status was later on modified by Kartush in 1994, where he added groups with different ossicular statuses while also considering certain non-ossicular but, nevertheless, significant middle ear characteristics.

2.2. Bellucci (1989) for Ottorhea

In 1989, Bellucci created a classification that categorized otorrhea in patients with chronic otitis media. In this classification, he divides otorrhea into 4 different stages based on the presence and the severity of discharge.

- Group A—Dry ear

- Group B—Occasionally wet

- Group C—Persistently wet

- Group D—Wet cleft palate

This classification is used to assess the type of otorrhea and the likelihood of infection in patients undergoing surgery. Presence of drainage has a statistically significant relationship with prognosis, with more drainage resulting in a worse outcome (OOPS).

2.3. SPITE Questionnaire (Black, 1992)

The Standardized Patient and Internal Therapy Evaluation (SPITE) is a questionnaire that was developed by Bruce Black in 1992. This questionnaire is filled out both preoperatively and postoperatively by patients undergoing surgeries of the ear, including ossiculoplasty. It is used as a tool to evaluate ear surgery, and it takes a broader approach since it takes into account the overall quality of life, severity of symptoms, and the impact of hearing loss on the patient’s life. The questionnaire is relatively extensive and is therefore divided into different domains such as surgical factors, prosthetic factors, infection status, tissue status, and eustachian status, among some other data gathered that did not fit into a specific domain. Questions asked that did not fit into a specific domain included the type of procedure, whether or not the procedure was a planned second stage, whether or not a prosthesis was used, the air-bone gap audiological results taken finally at 12 months postoperatively, and the main cause of failure occurring within the first 12 months postoperatively.

Black had a series of 535 ossiculoplasties that took part in this method of assessment to determine which of the factors within the questionnaire had a statistically significant association with adverse audiological results. Based on his findings, not all the factors within the different domains yielded statistically significant results. Within the surgical domain, whether or not the surgery was complex and if it required major scutum repair plus myringoplasty were both deemed statistically significant. Both the factors within the prosthetic domain, the status of the ossicular chain (considering malleus and stapes) and the air-bone gap at presentation, yielded statistically significant results. Similar to the prosthetic domain, both factors within the infection domain, which were unremitting otorrhea and chronic myringitis, had significant outcomes. With regard to the validity of the tissue, the need for myringoplasty at the time of ossiculoplasty was not significant, whereas the general condition of the patient, damaged or diseased mucosa, and meatoplasty involving the drum all had statistically significant results. Both the presence of effusion and severe collapse of pars tensa, factors making up the eustachian domain, were considered significant. Lastly, neither the staged procedure nor the type of prosthesis used, whether hydroxylapatite or Plastipore, was significant.

2.4. Kartush (1994)

Kartush used the original ossicular chain classification by Austin; however, he modified it by adding three more classes that emphasized fixation of the ossicles, even when all three ossicles are present. The groups he added were Group O (intact ossicular chain), Group E (ossicular head fixation), and Group F (stapes fixation).

With these three groups added, the modified Austin-Kartush classification for the ossicular status was created:

- Group O—M+, I+, S+

- Group A—M+, S+

- Group B—M +, S –

- Group C—M –, S +

- Group D—M –, S –

- Group E—Ossicle head fixation

- Group F—Stapes Fixation

Apart from modifying Austin's classification, Kartush created a more comprehensive scoring system for ossiculoplasty called the Middle Ear Risk Index (MERI), where he used the newly created Austin-Kartush classification for the ossicular chain, along with other variables deemed to have a clinically significant impact on the hearing results of ossiculoplasty. The other variables included Bellucci’s classification for otorrhea, presence of perforation, presence of cholesteatoma, granulation or effusion within the middle ear, and previous surgery. Kartush gave each of these factors within the index a score or a risk value, in increasing order of severity, which were summed up to provide a total MERI score. The minimum MERI score was zero, and the maximum was 12. Based on the cumulative score, he categorized the patients into 5 different prognosis/risk groups. Patients with a score of 0-1 (normal ear) had the best prognosis, 2-4 were common mild risk, 5-6 were common moderate risk, 7-11 were common severe risk, and lastly, patients with a cumulative MERI score of 12 had the worst possible prognosis, also referred to as end-stage ear.

2.5. Dornhoffer and Gardner (2001)

Another score to predict the outcome of ossiculoplasty was developed by John L. Dornhoffer and Edward Gardner in 2001. His scoring system, referred to as the Ossiculoplasty Outcome Parameter Staging (OOPS), emphasized middle ear factors and the type of surgery performed. Similar to Kartush’s MERI score, each risk factor received a score or a risk value based on the degree of impact it had on postoperative outcome. Within the middle ear, he focused on the ossicles, the presence or absence of drainage, and whether the mucosa was normal or fibrotic. With regard to the ossicles, he had three subgroups: normal ossicles given a risk value of zero, presence of malleus given a value of 1, and lastly, malleus absence with the most significant risk value of 2. The mucosa was given a risk value of zero when normal and 2 when fibrotic. Furthermore, when drainage was present for more than half of the times, as reported by the patient, a risk value of 1 was given; otherwise, it was considered to have a risk value of zero. The surgical factors considered were the type of surgery and whether the surgery was primary or revision. A canal-wall-up mastoidectomy had a risk value of 1, whereas a canal-wall-down mastoidectomy had a value of 2, and finally, when mastoidectomy was performed, a risk value of zero was given. Lastly, all revision surgeries had a risk value of 2, whereas primary surgeries had none. According to the OOPS classification, a minimum cumulative score of zero meant that the surgery had the least risk, whereas a maximum score of 9 was considered the riskiest surgery. In his study, Dornhoffer evaluated the results of 185 patients and 200 ears and applied his new scoring system (OOPS). He found a correlation with a coefficient of 0.8, which showed that the higher up your cumulative OOPS score, the greater the postoperative air-bone gap.

2.6. Ear environment risk (EER) scale (Gluth et al., 2025)

After 2 decades, a new scoring system was developed by Michael B. Gluth et al. in late 2024, referred to as the Ear Environment Risk (EER) scale. This new framework uses the previous scoring systems, such as MERI and OOPS; however, it attempts to resolve their limitations, such as small sample sizes, limited or narrow focus on very specific variables, and single-center data. For this reason, they conducted a comprehensive multi-center study with a long-term follow-up while also trying to validate their results with statistical significance. In this new study, several new variables were added that were deemed significant but missing from the previous stagings. The impact of all variables within the new scale was evaluated using statistical analysis within a population of 1,679 patients across the centers to determine their impact, if any, on postoperative hearing results. The variables within this new scoring are divided into three different domains: patient factors, ossicular status, and lastly, middle ear envelope. Through detailed statistical analysis (regression analysis), the correlation of each of the variables considered within the study was evaluated. The final EER scale consists of the variables that were found to have a statistically significant association with postoperative hearing. A score of 1 is given to first-time revision surgeries whereas for surgeries being repeated multiple times, a risk score of 5 is given. Furthermore, for canal wall down surgeries with the mastoid cavity present, a score of 2 is given, and for pediatric patients, a score of 1. With regard to the ossicular chain status, a missing or damaged malleus gets a score of 2, whereas a missing or damaged stapes suprastructure receives a score of only 1. Using Bellucci’s classification for drainage, a score of 1 was given only when the patient reported that the ear was wet for more than 50% of the time or when it was wet with a cleft palate. Finally, a lateralized or blunted tympanic membrane received a score of 4. The new Ear Environment Risk Scoring system has a maximum score of 16 and is divided into 4 different groups of risk based on their cumulative score. Patients with a total score of zero were considered favorable, those with a score of 1-4 were low risk, those with a score of 5-8 had intermediate risk, and lastly, patients with a cumulative score of 9 or more were deemed high risk. A positive correlation was found between the cumulative score and the post-operative air-bone gap, validating the pre-operative grouping of patients.

3. Limitations

The authors believe that although these scores provide great value, they each have shortcomings in some variables that have prognostic significance.

3.1. Bellucci’s classification

This classification solely focuses on the impact of drainage and does not take any other variables into consideration. Other variables well known to have an impact, such as ossicular status, have no role in this classification; therefore, unless used with other variables or as a part of another broader classification, its role in predicting postoperative ossiculoplasty hearing results is limited.

3.2. Austin’s Ossicular Chain Classification

As previously touched upon, the original classification served as a breakthrough for postoperative prediction, as it was the first classification. Nevertheless, the main limiting factor in this classification was the sole focus on the ossicular chain and the lack of emphasis on the condition of the ear as a whole, or even more broadly, the patient as a whole. Other variables such as granulation tissue and cholesteatoma, as well as edematous ear mucosa, have all been shown to negatively impact the hearing results of ossiculoplasty (Kim et al., 2010; Wiatr et al., 2019). This is why in 1985, Austin himself highlighted the importance of considering the overall health of the ear, rather than just the ossicles, taking factors such as otitis media, atelactatic otitis, and cholesteatoma into consideration. This was since it was well established that patients with more severe disease experienced a worse hearing result postoperatively and were more likely to present with complications (Austin, 1985). Furthermore, other variables such as type of ossicular replacement, whether PORP, TORP, or incus interposition, have been proven to have an impact on the prognosis of ossiculoplasty; however, they are not all considered in Austin’s original classification. Moreover, as shown in Table 1., neither the surgical history of the patient nor the type of surgery (canal wall up or canal wall down mastoidectomy) is touched upon.

Table 1. Comparison of Ossiculoplasty Scores.

	Bellucci’s classification	Austin Classification	Austin-Kartush Classification	Middle Ear Risk Index (MERI)	Ossiculoplasty Outcome Parameter Staging (OOPS)	Ear Environment Risk (EER) scale
Ossicular Chain Detail	None	Include information about the ossicular chain, but no detail about the middle ear		Uses Austin-Kartush to describe ossicles.	Normal or abnormal ossicular chain with or without malleus. Does not take Stapes into account	Uses Austin-Kartush to describe ossicles+ Stapes, Malleus, stapes fottplate fixation and lateral chain fixation assesed alone.
Middle Ear Detail	Only Otorrhea			Presence of tympanic membrane perforation, cholesteatoma, middle ear granulation/ Effusion	Presence of drainage and normal or fibrotic mucosa	Drainage, mucosal disease, cholesteatoma, granulation tissue, effusion, myringitis, tympanic membrane lateralized/blunted
Surgical Factors	None	None		Surgical History	Surgical History and type of Surgery (Canal Wall Up, Canal Wall Down or no mastoidectomy)	Revision surgery, type of surgery (intact canal wall, canal wall down)

3.3. Black’s SPITE Method for Assesment of Ossiculoplasty

SPITE by Bruce Black was the first method to consider the overall experience of the patient. It did this through a thorough pre- and postoperative questionnaire evaluation. It also considered other variables other than otorrhea and the status of the ossicular chain, such as the state of the mucosa, the preoperative ABG, whether or not the patient has had prior surgery, the status of the eustachian tube, and lastly, the type of material used in surgery. Although not all of them were found to have a statistically significant result, it was a step in the right direction as it considered factors such as the type of material used, primary or revision surgery, and eustachian tube function, all factors shown to have a significant impact in the literature (Choi et al., 2009; Kálmán et al., 2023; Olaison et al., 2024). With this being said, there were many variables not considered in this assessment method. Apart from eustachian tube dysfunction, another factor contributing to middle ear negative pressure is the presence of atelectasis, a phenomenon shown to impact ossiculoplasty prognosis but not considered in this paper (Vartiainen and Nuutinen, 1992). Furthermore, another variable not considered is the status of the tympanic membrane. Both perforation of the membrane and tympanosclerosis have been shown to significantly impact the postoperative hearing result (Teufert and De La Cruz, 2002; Selaimen et al., 2021). With regard to the ossicular status, the only ossicles considered are the malleus and the stapes. Although both are shown to be significant in the literature, the presence or absence of the incus is also significant (Bayazit et al., 2005). In the SPITE assessment method, the need for myringoplasty with major scutum repair is assessed; however, many other surgical variables, such as type of ossicular replacement (whether PORP, TORP, cartilage, or incus repositioning), are not assessed. Although whether the surgery was primary or secondary was assessed and found to not have a significant association, the reason for revision surgery was not considered in this method. According to the literature, cases requiring revision due to prosthesis extrusion yielded better results, as extrusion is usually associated with either prosthetic instability or biocompatibility issues. Both of these can be tackled with simpler techniques, such as changing the prosthetic material, therefore, more likely to lead to a more favorable outcome. In contrast to extrusion, revision cases due to fibrosis arise due to adhesion and scarring, generally requiring more invasive procedures to fix and therefore, more likely to result in complications such as further scarring, incomplete hearing restoration, or sensorineural damage (House and Teufert, 2001). Moreover, another variable not considered in this study was the type of tympanoplasty, since type 3 tympanoplasty has recorded much higher gain in postoperative hearing when compared to type 4 tympanoplasty (Kubo et al., 1993; Takahashi and Yamamoto, 2004).

3.4. Kartush’s Middle Ear Risk Index (MERI)

As aforementioned, Kartush modified the original ossicular chain classification by adding three different groups, mainly considering the fixation of ossicles. He also noticed the importance of other non-ossicular status variables such as otorrhea, perforation, cholesteatoma, middle ear effusion or granulation, and lastly, previous surgery. Each variable was also given a different score, based on the level of impact they had on ossiculoplasty outcome, and their individual scores were summed up to give a cumulative score, out of 12, used to predict the prognosis of ossiculoplasty. MERI served as a cornerstone for otologists for many years and is still considered one of the best prognostic tools. However, with many years of further research into the matter, many other variables are proven to have an impact on prognosis that are not mentioned in this scoring index. Although this score does take revision cases into account, similar to SPITE, no other surgical factors such as type of tympanoplasty or mastoidectomy are considered in this study (Kubo et al., 1993; Takahashi and Yamamoto, 2004). As mentioned, the type of mastoidectomy, whether canal wall up or down, is not considered in this score; however, according to Gupta and Kumar (2020), canal wall down ossiculoplasty is associated with a worse prognosis. In contrast to this, other authors, such as Karamarkar et al., state that no significant difference exists between canal wall down and canal wall up mastoidectomy (Bhatia et al., 1995). Furthermore, although the MERI score considers both cholesteatoma and granulation tissue, they are both given a score of 1, indicating that they are both considered to have equal impact. However, the authors have noticed that ossiculoplasty in patients with granulation tissue tends to have a worse outcome when compared to patients with cholesteatoma. This is further backed up in two different studies conducted by Wiatr et al. (Wiatr et al., 2014, 2015). Furthermore, other variables such as eustachian tube dysfunction, atelectasis, tympanosclerosis, and type of tympanoplasty, all shown in the literature to have significant prognostic value, are all not considered by Kartush in MERI (Vartiainen and Nuutinen, 1992; Kubo et al., 1993; Teufert and De La Cruz, 2002; Takahashi and Yamamoto, 2004; Choi et al., 2009).

Moreover, MERI does not consider the type of ossiculoplasty in the score; however, it is known that the type of ossiculoplasty, whether TORP, PORP, or incus repositioning, has a significant prognostic value. Olaison et al. (2020) showed that regardless of the prosthetic material used, PORP yielded better postoperative hearing outcomes. This claim was further supported by Vincent et al. (2011), which showed that PORP was not only providing superior hearing restoration but also had lower rates of extrusion. This better prognosis of PORP with respect to TORP can also be attributed to the presence of stapes suprastructure. Lastly, within the Austin-Kartush classification for the ossicular chain, Kartush has considered the malleus to be more significant than the stapes. However, the authors consider both the stapes and its footplate very significant for hearing since it has been observed that when the stapes is absent, the hearing outcome is very poor, especially for cases of mobile footplate (Boroń et al., 2020). Lastly, this scoring system does not consider the type of drum graft used. This is although some studies have shown better results with cartilage-perichondrium grafts when compared to temporalis fascia grafts, whereas other studies have shown temporalis fascia to have better short-term outcomes but with limited durability compared to that of cartilage and with more failure rates (Sood et al., 2018; Raman and Somaraj, 2019).

3.5. Dornhoffer and Gardner’s Ossiculoplasty Outcome Parameter Staging (OOPS)

In 2001, Dornhoffer introduced OOPS, which provided a cumulative score to predict prognosis. He considered drainage, mucosa, ossicular status, and surgical factors. This was the first scoring system to take canal-wall-up and canal-wall-down into consideration, a variable proven in the literature to be significant but missing from the other staging systems prior to it (Gupta and Kumar, 2019). Furthermore, many other significant variables, such as atelectasis, type of ossicular replacement, eustachian tube dysfunction, tympanosclerosis, perforation, cholesteatoma, granulation tissue, type of drum graft, reason for revision surgery, and type of tympanoplasty, were all neglected in this scoring system. Most importantly, OOPS only considers the presence or absence of the malleus in the ossicular chain to be significant, without considering the condition of the stapes or incus. This has been proven otherwise by many physicians since then that not only highlight the importance of the stapes and its footplate but also the presence or absence of the incus (Kartush, 1994).

3.6. Gluth et al.’s Ear Environment Risk (EER) Scale

This scale has been very recently introduced by Michael B. Gluth et al., which addresses the limitations within the previous scoring systems. What gives this latest score its relevance is its multi-center approach and robust statistical analysis to determine which variables have a statistically significant association with postoperative hearing. With this said, there are many variables that are not assessed for in this scale. Factors such as adhesive otitis media and fibrosis are known to have an impact on hearing outcome postoperatively. This is proven by Selvan and Karuppasamy (2017), who have shown that with adhesive otitis media, smaller improvements are gained in ABG. Moreover, although perforation of the tympanic membrane is considered, the location of the perforation has not been specified. The authors have noticed, and it has been shown in the literature, that marginal and central perforations yield different results, with marginal perforation yielding worse outcomes than central perforation (Selaimen et al., 2021). Still regarding the tympanic membrane, another variable of importance but neglected in this scale is tympanosclerosis, which is associated with a poorer postoperative outcome (Teufert and De La Cruz, 2002). Furthermore, this scale does not consider the type of tympanoplasty. However, many papers emphasize the difference between them and have shown that tympanoplasty type 3 has a better outcome when compared to type 4 (Kubo et al., 1993; Takahashi and Yamamoto, 2004). Also, the authors have noticed that the function of the eustachian tube is of utmost importance for postoperative outcome. Choi et al. (2009) also supported this claim when he showed that poor eustachian tube function is correlated with both suboptimal air-bone gap closure and reduced middle ear aeration after tympanoplasty. Apart from eustachian tube dysfunction, atelectasis is another that affects the middle ear negative pressure, as shown by Vartiainen and Nuutinen (1992). However, neither atelectasis nor eustachian tube dysfunction are assessed for in the ear environment risk scale. Moreover, although this paper does assess for the differences between TORP and PORP, it does not consider incus repositioning. Incus repositioning is a type of ossiculoplasty with its own indication and prognosis, with some papers finding better results with incus repositioning than with PORP and with fewer complication rates (Naragund et al., 2011; Amith and Mudhol, 2017). Another variable the author thinks is worth considering but is not in the scale is the type of drum graft. Different types of drum grafts exist, such as cartilage, temporalis fascia, and perichondrium. Each of these types has its own indication and prognosis. According to Raman and Somaraj (2020), cartilage provides a better outcome than fascia. As aforementioned above, this new scale is a significant breakthrough and improvement from the scoring systems prior to it; however, there still exists room for improvement.

Table 1. Comparison of the main ossiculoplasty prognostic scoring systems, emphasizing the variables with the greatest variability across the different classifications.

4. Modified Ossiculoplasty Score

CT scan finding (especially cone beam CT scan):

- Normal mastoid air cells and attic

- Retrotympanic opacity

- Attic or epitympanum opacity/erosion is a telltale sign.

- opacity around stapes

- Ossicular erosion/loss

- Excessive cholesteatoma

Middle ear negative pressure

- None

- Atelectasis

- Tubal dysfunction

Middle ear mucosa

- Normal middle ear mucosa

- Edematous

- Cholesteatoma

- Granulation Tissue and Cholesteatoma

Pre-op hearing/bone conduction

- Less than 30 dB

- 30–40 dB

- > 40 dB

Tympanic Membrane

- Normal

- Central Perforation

- Subtotal or Marginal

- Tympanosclerosis

Type of mastoid surgery

- No, cortical

- Canal wall up

- Canal wall down with obliteration

- Canal wall down without obliteration

State of ossicles

- Normal, just clearance.

- Malleus or incus fixation

- Incus loss

- Stapes superstructure (present or absent)

- If stapes suprastructure is present, is it mobile or fixed?

- Loss of all ossicles

Type of Ossicular Replacement

- Clearance

- Incus interposition

- PORP

- TORP

- Cartilage

Type of drum graft

- No myringoplasty

- Temporalis fascia or perichondrium

- Cartilage

Frequency of surgery

- First time

- Revision

If revision, what is the reason?

- Extruded

- Fixed

Type of tympanoplasty

- Type 3

- Type 4

Complicated ears that limit surgery

- Adhesive otitis media

- Lateral Semicircular Canal Fistula

- Floating footplate

- Facial nerve palsy

- Facial nerve dehiscence

5. Implementation of the Modified Ossiculoplasty Score

By taking the prior scores into consideration and incorporating our own experience, the aforementioned modified scoring system for ossiculoplasty has been developed. In this score, we have kept the variables we deem necessary from the previous scores while also trying to fill in the gaps we have found in the previous scores with new variables. Some of the variables, such as tympanic membrane perforation or state of ossicles, may have been touched upon in the previous scores; however, we have classified them in a different but more organized fashion, with support from the literature. Furthermore, apart from reorganizing variables present in the prior scores, we have also added variables that, although known to have a significant impact, are not considered in any of the previous variables. These include variables such as type of tympanoplasty, type of drum graft, preoperative hearing, CT scan (cone beam) findings, and complicated ears. Regarding the complicated ears, we have noticed that certain conditions need to be addressed prior to performing primary ossiculoplasty, since if not addressed, they tend to negatively impact the outcome of ossiculoplasty. These include adhesive otitis media, lateral semicircular canal fistula, facial nerve dehiscence, facial nerve palsy, and a floating footplate (Idiades, 2008; Fernández et al., 2023; Young and Ng, 2023). For these cases, patients should be notified that the ossiculoplasty should either be performed as a secondary surgery after correcting the primary defect or, for cases where the defect is not repaired, the outcome can be negatively impacted. This is because for cases of a floating footplate, inserting the prosthesis on top of it becomes difficult as the footplate can sink, while for cases of facial nerve palsy, inserting the ossicle might put further compression on the nerve and, hence, worsen the nerve palsy. With regard to CT scan findings, although surgeons might order a preoperative CT scan to evaluate the condition of the ear, no prior ossiculoplasty score or system has considered it as a part of their scale. We have listed certain findings that can be used preoperatively to determine the difficulty of the case and, possibly, the postoperative hearing outcome. These findings, in order of severity, include normal mastoid air cells and attic, presence of retrotympanic opacity, attic or epitympanum opacity/erosion telltale sign, opacity around the stapes, ossicular erosion or loss, and finally excessive cholesteatoma. As previously mentioned, there are studies that have evaluated the importance of preoperative CT scan findings in ossiculoplasty; however, this has never been considered as a variable in the previous score. According to Jung et al., one of the most favorable preoperative CT scan findings is an intact superstructure and malleus handle, which are shown very well on cone beam CT scans. In contrast, retrotympanic space soft tissue density and mucosal thickenings observed on CT scans are associated with lower ABG outcomes. With regard to middle ear aeration and pneumatization, hypopneumatized mastoid air cells observed on CT scans are associated with worse outcomes (Jung et al., 2025). Lastly, with regard to Bellucci’s classification, it has not been considered in this classification, as we think performing surgery in a wet ear does not lead to a favorable outcome and should be avoided. Although the individual parameters of this proposed scoring system are supported by the literature, we highly encourage fellow surgeons and researchers to conduct large-scale, multicentric studies to evaluate the impact of each of these variables on the outcome of ossiculoplasty, especially the parameters that are unique to this new system, so that a more comprehensive, validated scaling system can be developed with both statistical significance and clinical relevance.

6. Conclusion

With the recent updates and progression in ossiculoplasty, many new variables have been discovered that have an impact on the prognosis of the surgery. Therefore, the scores used to preoperatively predict the outcome have seen major progression throughout the years. In this review paper, we have summarized the different scores developed over time for ossiculoplasty and have proposed a novel, modified scoring system aimed at filling the preexisting gaps.

Funding Statement

This research did not receive any grant from funding agencies in the public, commercial, or not-for-profit sectors.