Study Examines Radiographic Outcomes After Cotton Osteotomy

A recent article in press with The Journal of Foot and Ankle Surgery evaluated radiographic short- to intermediate-term outcomes in patients that had Cotton osteotomies. The authors reviewed medical records of a single surgeon from between January 2006 and October 2018, including 61 patients and 71 feet that underwent Cotton osteotomies as part of flatfoot reconstruction. They looked at rates of union and complications, in addition to cuneiform articular angle (CAA) changes based on the type and size of the graft used.

In those who had radiographic follow-up for greater than nine months, the authors noted an overall complication rate of 5.6 percent (4/71). Comparing preoperative measurements to that of three weeks postoperatively, they found 0.91 degrees of correction of the cuneiform articular angle for every one-millimeter increase in graft wedge size. During that same time frame, they noted a change of 0.70 millimeters per one millimeter of graft used in the anterior-posterior medial cuneiform bisection dorsal length (AP length).

At six-to-10 weeks postoperatively, measurements revealed statistically significant changes in both of these measurements, as well. The authors concluded that the Cotton osteotomy showed a statistically significant loss of correction between six and 10 weeks postop, specifically, at the time when the patients’ postoperative protocol allowed them to begin bearing weight on the operative foot. The authors further contend that metal grafts may contribute to maintaining correction and advocate for further study regarding their efficacy.

Brian Au, DPM, AACFAS, lead author on the study, says that a 2018 study by Kunas and colleagues also used the cuneiform articular angle as a data point.¹ He goes on to say that he hoped to identify another useful measurement for the Cotton osteotomy. In collaboration with Patrick Burns, DPM, FACFAS, he and his team began to review Cotton osteotomy cases performed by Dr. Burns at the University of Pittsburgh Medical Center, in Pittsburgh, PA.

“We wanted to see how well certain allograft/metallic grafts would hold up and the overall loss or maintenance of correction in terms of the cuneiform articular angle. We also developed another measurement using the anterior-posterior length of the medial cuneiform on an AP X-ray,” he says.

Dr. Au, in practice in Orange, CA, feels the Cotton osteotomy is a powerful procedure that belongs as a choice in a comprehensive flatfoot reconstruction toolkit. He feels the fairly low complication rate (two cases of neuritis and two asymptomatic non-unions) is an impactful data point in the study. He adds that they also found that the grafts used generally did well without additional plating or screws, with the majority of wedges employed being seven or eight millimeters. Although they did identify significant loss of radiographic correction postoperatively in this cohort of patients after Cotton osteotomy, he points out that this did not ultimately translate into symptoms at the Cotton site or midfoot.

Dr. Au says they found a statistically significant loss of radiographic correction during the postoperative period for Cottons, however this did not translate into any significant symptoms at the Cotton site/midfoot.

“Using a larger initial graft may help to offset the loss,” he says. “Although there was a trend (in our study) for metallic grafts maintaining correction, more data is needed to determine if they provide significant maintenance of correction postoperatively.” 

Which Chairside Tests For Diabetic Peripheral Neuropathy Are Most Reliable?

A recent systematic review in BMJ Open Diabetes Research and Care evaluated the reliability of various chairside methods of diagnostic testing for diabetes-related peripheral neuropathy (DPN). The authors included 17 eligible studies performed up to May 2021. Pool analysis supported the reliability of vibration perception threshold (VPT), ankle reflex testing, and four-site monofilament, as recommended by the latest guidelines, for screening and monitoring of DPN. However, there was not a clear conclusion regarding the reliability of temperature perception, pinprick, proprioception, three-site monofilament and Ipswich touch test in this study.

Lawrence Lavery, DPM, MPH, feels that evaluation for DPN starts with symptoms.

“If you ask the right questions, often patients will tell you they have sensory neuropathy,” he says.

He goes on to say that patients may relate numbness, tingling, formication, temperature inconsistencies, or feeling like there is mud caked on the sole of the foot when they wear a thick sock, all potential indications of large-fiber neuropathy. For patients with small-fiber neuropathy, he says patients relate burning, electrical or lancinating pain, often worse at night that interrupts sleep.

In his experience, Dr. Lavery feels the easiest screening tools for large fiber neuropathy are a 128 Hz tuning fork to evaluate vibration sensation and the 10 gram monofilament to evaluate pressure. Additionally, he finds that Achilles deep tendon reflex testing is an option, but more difficult to interpret, especially for clinicians that do not routinely perform it on a wide cohort of patients. Small fiber neuropathy, he says, is not often tested chairside, since it relies on differences in temperature perception. And, relates that he finds most physician-oriented diagnostic texts do not include evaluation for sensory neuropathy. Overall, he points out that one can train a technician to obtain a history and perform certain testing.

“Unforunately, I do not think neuropathy is often evaluated in clinical practice by primary care physicians, internists, or podiatrists,” says Dr. Lavery, a Professor in the Department of Plastic Surgery at the University of Texas Southwestern Medical Center. “I have worked with residents and fellows for 25 years. Even when tuning forks are provided, they are not often used. The testing is easy and inexpensive.” 

How Do Patients With A First Lateral Ankle Sprain Fare After One Year?

How long might certain symptoms persist after a patient experiences a first lateral ankle sprain? An in-press systematic review in Foot and Ankle Surgery that included 15 studies examined this very question. Researchers specifically looked at subjective instability, re-sprains and remaining symptoms. The authors found presence of subjective instability in 37.9 percent of patients three months post-sprain,16.1 percent at six months, and 8.1 percent at 12 months after injury.

Recurrent lateral ankle sprains occurred in 15.8 percent of those in the cohort at 12 months after the initial sprain. Regarding residual pain, the authors noted 48.6, 21.5, and 6.7 percent of patients experiencing this at three, six, and 12 months post-sprain, respectively. They concluded that a longer period of non-operative treatment may be in order prior to pursuing surgery after a first lateral ankle sprain.

Marlene Reid, DPM says that, in her experience, most patients will not see a podiatrist for that first lateral ankle sprain, instead pursuing icing and modifying activity. They may go to an emergency department, but she notes that overall she finds they do not get appropriate stabilization.

“Often these patients can expect an eventual decrease in swelling and/or pain, but they are likely to experience multiple future sprains due to chronic instability,” she explains.

For those that do seek podiatric care, she feels that they typically do undergo proper immobilization and stabilization, assuming surgery is not indicated. In these cases, she says she observes patients experiencing the same level of stability as pre-injury after a period of rehabilitation, with some increases or decreases possible.

Dr. Reid points out that this particular review did not distinguish among the types of initial treatment for those first lateral ankle sprains, so she feels this significantly decreases the reliability of the findings. She was pleased that contributing biomechanical issues, including rearfoot instability were a part of the review, but feels that foot type, ancillary injuries and initial treatments chosen should have been part of the investigation.

Although the value of the study, in her opinion, was not high, she did feel that some of these outcomes could improve if patients in question sought podiatric treatment.

“The 12-month findings, in my opinion, are unacceptable and unlikely if a podiatric physician initiates treatment,” says Dr. Reid, a Past President of the Illinois Podiatric Medical Association and the American Association for Women Podiatrists. 

1. Kunas GC, Do HT, Aiyer A, Deland JT, Ellis SJ. Contribution of medial cuneiform osteotomy to correction of longitudinal arch collapse in stage IIb adult-acquired flatfoot deformity. Foot Ankle Int. 2018;39(8):885-893.