Talipes Equino Varus: A Preliminary Review of Denis Browne-Bar Bracing

By Sophy Puth, Orthotics Resident
Michael Sussman, MD
June 30, 2004
Shriners Hospital for Children
Portland, Oregon

Abstract

Seventy-four patients with the diagnosis of idiopathic congenital talipes equinovarus were reviewed in this retrospective chart analysis to determine the rate of recurrence of the foot deformity at Shriners Hospital for Children in Portland, Oregon. Each patient was treated with the Ponseti technique between the years 2000 and 2003. Infants with any other congenital abnormality were excluded from this review. General patient information, such as gender, age, side involved, race, and severity of deformity were collected. Parental information was also reviewed including family history of clubfoot. Each patient was treated with serial manipulation, corrective castings, and Denis Browne Bar bracing. Nineteen patients failed to tolerate the DBB brace and were prescribed custom made corrective AFOs. The recurrence rate with the use of the AFOs (16%) was significantly lower than that of the use of the DBB braces (46%). It was found that the rate of recurrence reduced with increased wear time as evident with zero recurrence in those eleven patients who were able to tolerate the DBB braces at least two months full-time followed by at least twelve months of nocturnal wear. It was also noted that the recurrence rate in patients who began DBB brace treatment at or before the age of three months was approximately half the recurrence rate of those older than three months of age. Lastly, the trend shown is this review in regards to the initial position of toe-out set on the DBB brace indicated a higher recurrence rate correlating with a greater degree of initial toe-out.

Around 400 BC, Hippocrates first documented a procedure for treating clubfeet. He recommended, of all things, gentle manipulation of the foot followed by splinting.¹

Through the years many different procedures have been tried and tested with varying results, including forceful manipulation and extensive surgical releases. Between 1970 and 1990 there were many "positive" reports on the correction of clubfeet utilizing comprehensive open release surgeries. We now know that there are many long-term complications of such surgeries. These include recurrence, over-correction, stiffness and pain.² Due to these complications, and a more consistent success rate with non-surgical procedures, physicians are once again opting for more conservative methods in treating these deformities. The current gold standard in North America for the initial treatment of idiopathic congenital talipes equinovarus (clubfoot) is the non-operative technique described and developed by Dr. Ponseti of Iowa in the 1940s. This method includes proper gentle manipulation, serial casting, percutaneous tendo-achilles lengthening (TAL) when necessary, and Denis Browne-Bar orthotic bracing combined with corrective shoes. These braces are to be worn full time for two to three months and then nocturnally for up to four years. Initially, Ponseti reported good correction in 89% of the cases with a relative recurrence rate of about fifty percent.³ Later, Morcuende and Ponseti at the University of Iowa Clinics found that this treatment along with limited operative procedures produced clinically successful results in 98% of clubfeet cases. This study documented an improved rate of relapse of only eleven percent.⁴ The long term studies of this method have also shown a high success rate.^5,6 Today, this method continues to be more successful and least likely to result in recurrent clubfoot deformities than any other documented technique in the literature.

Despite the long-term success found with the Ponseti method, recurrent clubfoot deformities after the initial correction with serial casting and manipulation still persists. Matthew Dobbs, MD and his associates recently documented in his study of fifty-one infants that failure with the Ponseti method is most often attributed to noncompliance with the use of the Denis Browne-Bar orthotic brace. Two of the most common factors predictive of recurrence identified by this study were parental educational level (high-school education or less) and noncompliance.⁷ This Retrospective study defined "noncompliance" as a patient who discontinued the use of the Denis Browne Bar brace before the end of the prescribed protocol. It has been noted in other studies including Dobbs study that non-compliance is extremely difficult to objectively define since it is clearly multifactorial and subjective in nature.

Given the success rate of the Ponseti technique, Shriners Hospital for children in Portland has been using this method for treating patients that present with clubfeet deformities now since the year 2000. The Denis Browne Bar Brace utilizes straight last shoes interlocked and positioned by a metal bar producing approximately 15 degrees of dorsiflexion and 70 degrees of relative toe-out or external rotation. The brace is generally worn twenty-three hours a day for two to three months and then nocturnally once the infant begins to pull up to stand. Perhaps unique to the Portland hospital, the physicians will occasionally prescribe a corrective plastic solid-ankle AFO as an alternative option for the treatment of clubfoot if the child is unable to tolerate the Denis Browne Bar Brace. So far, this is prescribed only as a secondary alternative to the Denis Browne Bar and has resulted in some observed clinical success.

The purpose of this study is to determine the rate of completion of the prescribed Denis Browne-Bar brace regiment and to review the rate of recurrence among the patients diagnosed with clubfeet at the Shriners Hospital for Children in Portland (SHCP). We will compare identified factors such as patient demographics, specific bracing data, and parental information to the rate of recurrence. This retrospective analysis will enable us to compare our recent rate of success with other documented standards in the literature. We will not study noncompliance because it is very difficult to assess objectively and because many patients were prescribed corrective AFOs if they could not tolerate the Denis Browne Bar brace. Nevertheless, compiling this statistical information will allow SHCP physicians and support staff the means to evaluate their current treatment protocol, and identify a potential need to establish new bracing alternatives. This study will also compile preliminary data to be used to conduct prospective research comparing different brace options with the ultimate goal of improving clubfoot case outcomes.

Methods

The cases of seventy-four infants with idiopathic congenital talipes equinovarus who had been treated with the use of the Ponseti method by physicians at the Portland Shriners Hospital for Children were retrospectively reviewed. Approval for this chart review was obtained from the institutional review board at Oregon Health Science University. Patients were excluded from the review if they presented with other underlying diagnoses or congenital abnormalities, or had received initial treatment inconsistent with the conservative Ponseti method. The degree of deformity was rated as mild, moderate, or severe using an informal classification system. Mild was defined as a hyper supple foot where passive over-correction was possible; moderate was defined as a typical clubfoot presentation, but one that had more flexibility and was correctable to a position close to neutral; and severe cases were defined as relatively rigid feet incapable of passive correction close to neutral. A more systematic grading scale such as the one formulated by Dimeglo et al. was not used due to incomplete documentation at initial patient screening.

The age of the infant at the time of their first fitting with the Denis Browne Bar brace was recorded. Also noted was the initial degree of toe-out ordered by the physician. The lengths of full-time and nocturnal wear, and any event requiring the physician to discontinue treatment with the Denis Browne Bar brace were included as well. The potential reasons for the discontinuation of the DBB brace included in this review were patient intolerance; fitting issues; physician preference; recurrence of clubfoot; or a completed protocol. Recurrence at any phase of the treatment was documented and the follow-up treatment was recorded. Also included in the survey were those patients who were prescribed an AFO if he or she could not tolerate the Denis Browne bar and straight last shoes.

Demographic data collected from patient files included gender, date of birth, and race of the infant. The marital status, primary spoken language, and annual income of the parents were collected as well as the presence or absence of a family history of clubfoot.

All data was collected and analyzed in reference to rate of recurrence to show general trends and significant differences in this preliminary review. The intent of this study was therefore not to identify concrete conclusions but rather to further add to the continued discussion of clubfoot treatment already produced within the literature.

Results

The files of seventy-four infants (113 feet) with idiopathic clubfoot deformities were reviewed. Forty-nine (66%) of the seventy-four patients were male. Fifty-six infants (76%) were Caucasian, fifteen (20%) were Hispanic, and three were of other races. The parents of forty-nine infants (66%) were married, and the parents of sixty-seven patients (91%) spoke English as their primary language. Forty-three (58%) of the families reported annual incomes of less than $20,000. Twenty-four (32%) of the patients reported having a family history of clubfoot deformity.

Of the seventy-four infants, thirty-five (47%) had unilateral involvement and thirty-nine (53%) presented with bilateral involvement. Of the 113 feet treated sixty were right feet and fifty-three were left feet. The level of deformity was characterized as mild in fourteen feet (12%), moderate in sixty-three feet (56%), and severe in thirty-six feet (32%).

All seventy-four patients achieved initial correction with serial casting and manipulation, and were then fit with the Denis Browne Bar and straight last shoes. Thirty-four infants (46%) had partial recurrence of the clubfoot deformity at some point following the initial fitting. Eighteen of these had repeat serial castings and twenty-three had surgeries, including fourteen comprehensive releases, six tendo-achilles lengthenings (TALs), and three anterior tibialis transfers.

In terms of wear time achieved by this patient population, forty-nine patients (66%) completed a length of full-time wear greater or equal to two months as recommended by the Ponseti method. Despite this, eighteen of the forty-nine infants (37%) had recurrence, and seven required surgeries other than TAL following the event of recurrence. In addition, eleven infants completed a treatment of two months or greater of full-time wear followed by twelve months or greater of nocturnal wear. Of these eleven, there were no cases of recurrence!

It was noted that twenty-five infants wore their DBB full-time for less than two months and sixteen of these infants (64%) had recurrence. Ten of these sixteen infants required surgeries other than TAL following recurrence.

Chart 1. Rate of Recurrence versus Denis Browne Bar wearing time. Trend showing decreased recurrence rate with those patients who were able to tolerate more time in the brace. The first column represents those who did not tolerate the minimum of two months of full-time wear. The middle column is representative of those patients who tolerated full time for at least two months. The third column represents those who tolerated at least two months of full time wear followed by at least twelve months of nocturnal wear of the denis browne bar brace.

The age of the patient during the initial fitting varied. There were twenty-nine infants who began wearing the DBB brace at age three months or younger, and of these, only nine infants (31%) had recurrence of the clubfoot deformity and seven (24%) required follow-up surgery. However, of the forty-five infants who were older than three months of age when they began DBB bracing, twenty-five (55%) had recurrence and sixteen (36%) required follow-up surgery. (See pie chart 2)

Chart 2. Fitting Age Comparison. Recurrence of patients who were fitted with Denis Browne Bar Brace at three months of age or younger versus at greater than three months of age

There were nineteen patients out of the total seventy-four who were prescribed solid-ankle corrective AFOs prior to any recurrences and only after legitimate attempts were made with the DBB brace. Eight of the nineteen were fit with AFOs due to fitting issues such that the infants were able to pull out of the DBB shoes. The additional eleven of the nineteen infants were, according to parental verbal reports, never able to tolerate the DBB brace and were then issued corrective AFOs. Of these nineteen patients who were fit with corrective AFOs, only three (16%) cases later had documented recurrences.

Chart 3. AFO vs. DBB Bracing, Rate of recurrence significantly less (16%) with patients who used AFOs as their primary orthosis in maintaining the correction achieved with the Ponseti method.

The initial toe-out setting of the DBB brace was undocumented in three cases, thus reducing the number of cases considered by this variable to seventy-one. Thirty-two (45%) of the seventy-one infants began the DBB brace treatment with an initial toe-out position ranging from 20° to 35°, and thirty-nine infants (55%) were placed at an initial range between 40° and 70°. There was a rate of recurrence of 28% among the infants whose initial toe-out position was 35° or less, and a 59% rate of recurrence among the patients who were initially placed at a degree greater than thirty-five. (See Table 2 and Chart 4)

Chart 4. The rate of recurrence versus the initial position of toe-out in degrees

Fifty patients (68%) had a tendo-achilles lengthening during the serial casting phase due to an excessively tight heel cord. Twenty-six of these patients (52%) had recurrence and twenty (40%) required open corrective surgery. Twenty-four infants did not have a TAL. Eight of these infants (33%) had recurrence and three (13%) required open corrective surgery. Thirty-one out of fifty (62%) who had a TAL were able to tolerate the DBB brace full time for greater than two months, compared to eighteen out of 24 infants (75%) who did not have a TAL and yet were still able to tolerate the DBB full time for greater than two months.

Discussion

It has been found within literature that the primary risk factor for recurrent clubfoot deformities in infants who have had initial correction with serial manipulations and cast applications as outlined by Ponseti is noncompliance with the Dennis Browne Bar brace system.⁷ True compliance, however, is almost impossible to measure objectively. In addition to this, it is difficult to conclude whether non-compliance with the use of the Denis Browne Bar brace caused recurrence of the clubfoot deformity or rather that non-compliance is a reflection of recurrence which caused the brace to be less tolerable. Clinically, it was necessary to attempt other bracing systems since it was documented that tolerating the DBB brace with shoes for these infants was extremely cumbersome and therefore the rejection rate for them seemed to be quite high. Therefore, corrective AFOs that were not attached to a bar were attempted in those children who still had correction but could no longer tolerate their DBB braces.

As the numbers seems to indicate, custom-made corrective AFOs were found to be a legitimate alternative to DBB bracing within the principles used in the Ponseti technique. This could be stated with some confidence since the rate of recurrence with the AFOs (16%) was quite lower than the recurrence rate for those who wore the DBB braces (46%). There are a few concerns with the use of this bracing method, however, that should be objectively addressed in a future prospective study. These include the question of whether or not the AFOs would provide as much corrective forces as the DBB braces. Also, would it be advantages to cross the knee joint in hopes of gaining more control of the corrective abduction and dorsiflexion forces? Furthermore, adding another step of fabricating these custom AFOs would make accurate documentation of position and control that much more difficult since each brace would be unique.

The purpose of any orthosis is to maintain the correction achieved with serial casting and manipulation. As stated earlier, clubfoot is defined by four variables including equinus, varus, adductus of forefoot, and cavus. Therefore it would make sense that these variables need to be corrected sufficiently prior to bracing. The Ponseti method as outlined within the literature states that the involved foot should be stretched to at least 70 degrees of abduction from neutral passively and dorsiflexed to at least 15 degrees. This is achieved with serial manipulation, casting, and tenotomy when necessary. In our study, it is unclear if this was achieved consistently prior to bracing with DBB since documentation was lacking and multiple physicians were involved, deciding independently whether or not to proceed with bracing. We can however assume that some amount of correction was obtained after serial casting and that in our review the braces were prescribed as devices intended for the sole purpose of maintaining this correction.

A significant finding in this review of Denis Browne Bar bracing was that only fifteen percent of the patients completed at least two months of full time wear followed by at least twelve months of nocturnal wear. As reported, there was no recurrence among this group of patients. The data also seems to indicate that those who tolerated full time bracing with the Denis Browne Bar longer had fewer recurrences, as the difference in the rate of recurrence was twice as likely in infants who wore the DBB brace full time less than two months. Obviously, this data is important to clinicians as it should be used to educate parents as to why their child would benefit from consistent and continued use of the bracing systems.

The method by which the patients with clubfeet in this study were classified was subjective and based on the limited documentation. However, it appears clear that the rate of success is higher for those who have mild deformities compared to those who were initially classified as having severe clubfoot deformities.

Another clear observation from this review is that earlier intervention improves success. There was nearly twice the rate of recurrence found in patient who began bracing after three months of age versus those who began bracing younger. Although more recent literature suggest that even children over the age of one year still benefit from the conservative treatment methods, it is obvious that earlier intervention is preferred. This data lends itself to the principle that younger babies are generally more flexible and thus more correctable than older infants.

Lastly, it was a surprising and interesting discovery that the initial position of toe-out placed on the DBB brace and shoes seemed to show correlation with the rate of recurrence. One might have expected that the initial position of toe out was a reflection of the amount of correction and flexibility that was achieved prior to bracing. If this were true, then one would also have expected that the more toe out there was in the initial fitting the more easily the infant should have been able to tolerate the brace and the less recurrence there should have been. However, this review showed just the opposite. The trend with the data showed a higher rate of recurrence with a higher initial position of toe-out. This is not completely clear and more data would have been useful here such as the ending position of toe-out since it was the intension of physicians to have this toe-out position increased with every follow-up visit and weekly if parents were trusted to do this on their own. Unfortunately, this information was not clearly documented and could not be extrapolated from the patients' charts. It appears that moderation, once again, could be the key, and beginning the position of toe-out at a lesser degree with the goal of increasing this with time, thus building tolerance to the brace slowly, may very well improve outcome with the use of the Denis Browne Bar bracing system.

In conclusion, the conservative Ponseti method once again has been used fairly successfully in reducing the need for open surgeries to treat idiopathic congenital talipes equinovarus. There is, however, much room for improvement with documentation and clubfoot scoring methods at Shriners Portland. In addition, it appears that a prospective outcomes study or studies would be useful to determining the efficacy of specific bracing techniques that follow correction with serial castings.

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