Can High-Resolution Ultrasound Provide A Quicker, Accurate Diagnosis Of Osteomyelitis?

While physicians can use X-rays or magnetic resonance imaging (MRI) to help diagnose osteomyelitis, a new abstract to be presented at the Symposium on Advanced Wound Care Spring/Wound Healing Society (SAWC Spring/WHS) meeting later this month notes that high-resolution ultrasound is also effective in detecting the bone infection.

The study focused on 68 patients with chronic wounds and a clinical suspicion of bone infection. The abstract authors obtained high-resolution ultrasound scans with a device that had a 5-18 mHz linear array transducer. The patients in the study also had an X-ray and a MRI. Researchers considered patients positive for osteomyelitis if the ultrasound revealed a hypoechoic to anechoic zone adjacent to the cortex of the bone reflecting elevation of the periosteum (subperiosteal abscess) and direct connection of the echoless zone with the wound (fistula formation) and cortical interruption. High-resolution ultrasound had a 97 percent sensitivity and 92.8 percent specificity for osteomyelitis, according to the study.

Andrew Meyr, DPM, sees high-resolution ultrasound as a reasonable option for diagnosing osteomyelitis but no better than radiographs or MRI.

“I would consider it another tool used to help make the diagnosis of osteomyelitis but, in most cases, it should be more of a clinical diagnosis with imaging studies providing some evidence in support of or against the clinical diagnosis,” notes Dr. Meyr, an Associate Professor within the Department of Surgery at the Temple University School of Podiatric Medicine in Philadelphia.

James McGuire, DPM, cites “distinct advantages” in having an accurate modality to perform an immediate clinical assessment of possible osteomyelitis when prompt intervention may be necessary. He says it often takes more than a week to get MRI results back.

Cortical disruption, sinus tracts to bone and deep abscesses with high risk for bone infection are all findings that would show up much earlier on ultrasound, according to Dr. McGuire, an Associate Professor in the Departments of Podiatric Medicine and Biomechanics at the Temple University School of Podiatric Medicine.

The abstract notes that high-resolution ultrasound costs 75 percent less than MRI but about twice as much as X-rays. Since most insurances cover ultrasound diagnostics, once the diagnostic test is more common in clinics, Dr. McGuire says DPMs will find ultrasound machines a very worthwhile investment. Furthermore, he notes ultrasound has great utility and one can use it for many other purposes such as assessing deep wounds, sinuses and deep tissues in addition to soft tissue diagnosis, injection and biopsy guidance.

“These should make the purchase of an ultrasound a wise choice for clinics trying to get fee-for-service reimbursement in addition to better outcomes when/if we move to an outcome-based reimbursement system,” says Dr. McGuire.

Dr. Meyr feels a foreseeable problem with an ultrasound evaluation is that it would be very reliant on the person performing the test. He notes that some clinicians are better than others at reading the results.

“If people are completely dependent on an ultrasound to tell them whether there is osteomyelitis present or not, they are probably in a little bit of trouble. However, I do think it can be a useful tool to provide evidence or clues toward a diagnosis,” says Dr. Meyr.

The SAWC Spring/WHS meeting will be April 29 to May 3 in San Antonio, Texas. For more info, visit www.sawcspring.com .

What A Six-Year Retrospective Study Reveals About DFU Recurrence

By Brian McCurdy, Managing Editor

In a six-year retrospective study of 268 patients with either single or multiple diabetic foot ulcerations (DFUs), nearly half of the patients had recurrence of at least one ulceration, according to a recent abstract presented at the American College of Foot and Ankle Surgeons (ACFAS) Annual Scientific Conference.

The study authors note that approximately 60 percent of the patients with DFU recurrence reulcerated within one year of their initial presentation and 33 percent of the patients reulcerated between one to three years after their initial presentation. Over 53 percent of reulcerations occurred in areas of previous ulceration, according to the study abstract.

The fact that 53.6 percent of ulcers recurred in the same area as the initial ulceration underscores the importance of proper offloading and monitoring of skin integrity as well as possible correction or resection of the underlying deformity, according to the study. In order to prevent recurrence, the authors advocate close follow up during the time period after complete wound healing, which they define as epithelialization of the entire ulceration.

Ulcer recurrence may be more challenging than the actual treatment for healing a diabetic foot ulceration, notes abstract author Georgeanne Botek, DPM. She and her colleagues at the Cleveland Clinic recently started prescribing custom foot inserts based not only on the shape of the foot (such as a mold taken from a foam box) but plantar pressures as well using the Emed system (Novel). When building a custom insole to maximally offload the site of previous ulceration and underlying high plantar pressure, Dr. Botek cites research noting that a more effective insole can help in the prevention of recurrent plantar metatarsal head ulcerations.

“It never ceases to amaze me when my longtime, high-risk neuropathic patients admit that they do not wear their prescription footwear in the home,” says Dr. Botek, the Medical Director of the Diabetic Foot Clinic at the Cleveland Clinic.

By consistently and simply reexamining the efficacy of prescription footwear, Dr. Botek says we can determine if surgical care or modifying the existing prescription footwear is indicated. She notes one may prevent elevated plantar pressures through more advanced insoles and bracing in order to avoid pre-ulcerative calluses, thereby reducing potential ulceration. Dr. Botek stresses the importance of patient education at each and every visit, whether it is reinforcing the need for prescription footwear or getting patients to moisturize calluses and examine their feet daily.

Is A Bilayered Skin Substitute Effective For Severe Ulcerations In Patients With Multiple Comorbidities?

By Brian McCurdy, Managing Editor

A new abstract to be presented at the SAWC Spring/WHS meeting confirms that a bilayered bioengineered skin substitute is effective in treating severe lower extremity ulcers in patients with multiple comorbidities.

The abstract compared 158 patients with lower extremity ulcers who were treated with the bilayered skin substitute to 126 control patients with lower extremity ulcers. The follow-up period was 180 days. The study authors found that nearly 28 percent more ulcers healed in the bilayered skin substitute group (69.84 percent) in comparison to the control group (41.98 percent), even though the patients in the bilayered skin substitute group were deemed to be sicker with larger wounds. The average time to wound closure was 70.1 days in the bilayered bioengineered skin substitute group in comparison with 118.03 days in the control group, according to the abstract.

Kirsti Diehl, DPM, a co-author of the abstract, notes that the bilayered bioengineered skin substitute provides living cells, proteins, cytokines, growth factors and collagen to the non-healing chronic ulcer. This allows the ulcer to advance beyond a non-healing state with the promotion of cell differentiation and proliferation, and the reduction of fibrosis, according to Dr. Diehl.

When a chronic non-healing ulcer lacks the basic components needed for healing and has exposure to an abundant amount of these necessary components in the form of the skin substitute, restored healing capability occurs, notes Dr. Diehl, a Podiatric Medicine and Surgery Fellow in Clinical Research in Limb Preservation and Tissue Repair with the Veterans Affairs New England Health Care Division in Providence, RI.

Dr. Diehl says this skin substitute is indicated for patients with non-infected partial and full thickness venous leg ulcers and full thickness diabetic foot ulcers (DFUs) that do not extend beyond the dermis. She says one should consider the skin substitute when standard wound care efforts have failed (one month for venous leg ulcers and three weeks for DFUs).

Dr. Diehl cautions that patients with critical limb ischemia will experience a high failure rate with the skin substitute but patients with mild to moderate occlusive peripheral arterial disease (PAD) can experience positive healing outcomes.

“Of course, those with fewer patient comorbidities and non-smokers are likely to see better outcomes but our “real world” results show that the bilayered bioengineered skin substitute studied is capable of helping ulcers on very sick patients with multiple comorbidities as compared to the standard of care,” says Dr. Diehl. 

Is A Third Screw Beneficial For A Lapidus Arthrodesis?

By Brian McCurdy, Managing Editor

Adding a third intermetatarsal screw to the Lapidus arthrodesis may improve the stability of the construct, according to an abstract presented at the recent ACFAS Annual Scientific Conference.

The abstract authors assessed the rate of intermetatarsal screw failure with a modified Lapidus screw technique. Ninety-five patients (105 feet) were part of the study and surgeons performed a modified Lapidus arthrodesis, placing a third intermetatarsal screw either through a plate or independent of a plate. In the final X-ray, 92.4 percent of screws were intact according to the abstract with authors attributing that to proper joint preparation, standard fixation and an inherently stable construct.

In his experience, abstract lead author Lawrence DiDomenico, DPM, FACFAS, has found the third screw provides additional, stronger fixation and helps reduce the intermetatarsal angle. However, experience and this study have shown him that the third screw does not have a substantial effect on the timing of post-op weightbearing.

The study results also suggest that the third screw does not appear to have any significant long-term effect on outcomes for patients who have the Lapidus procedure, according to Dr. DiDomenico, the Section Chief of the Department of Podiatry at St. Elizabeth Hospital in Youngstown, Ohio and the Director of Fellowship Training of the Reconstructive Rearfoot and Ankle Surgical Fellowship in Youngstown, Ohio.