Foot & Ankle International

The use of retrospectively acquired preoperative AOFAS rating scores in clinical research to assess the outcomes of elective foot and ankle surgery has not been validated. The data obtained utilizing this methodology may misrepresent the results and lead to spurious conclusions. This investigation compared preoperative AOFAS Ankle-Hindfoot scores obtained before and after surgery from patients who had undergone elective surgery to determine if retrospectively acquired scores match those collected prospectively.

Only two out of 47 patients (4%) recalled identical AOFAS scores. The mean difference between the preoperative scores (preoperative score obtained after surgery minus preoperative score obtained before surgery) was −5.3 points. Fifteen patients (32%) had preoperative scores that differed by 20 points or more. Kappa statistics found little agreement among the five elements that comprised the two preoperative scores when responses obtained before and after surgery were compared to one another. The results suggest that preoperative clinical rating scores obtained after elective surgery are a poor predictor of the patient's preoperative condition and that studies which employ retrospectively acquired preoperative AOFAS clinical rating scores may overestimate the benefit of surgery.

The AOFAS foot scores are four related outcome instruments based on the use of quantitative interval data and have seen increasing use in the literature. The mathematical construction of the scales is particularly notable for a very small number of intervals available to answer each component item and for quantitatively unequal intervals for some items. Monte Carlo computer modeling techniques were used to simulate the responses to each item for a variety of idealized patient populations with several different means, standard deviations, and levels of interaction between items. The continuous data describing each patient's responses were categorized into the finite number of available intervals in the AOFAS Hindfoot score. The resultant distributions of net scores often demonstrated bizarre, skewed behavior that bore little resemblance to the original distributions of continuous data. The effects were magnified as the ends of the scale were approached and when strong correlations between the items measuring pain and function were present. The distributions did not become distorted when the original continuous data were not rounded off into intervals but were simply weighted by their relative contribution to the AOFAS score and summed. The AOFAS scores, therefore, have inherently limited precision which is entirely due to the small number of response intervals available to answer each component item of the scale. Minor changes in a patient's response to a series of correlated questions can potentially make a drastic difference in their total score. Because the population distributions may be badly skewed, the use of parametric statistics with the AOFAS scores should be regarded with genuine suspicion, and appropriate refinements of the scales should be sought.

We studied the validity and reliability of the Foot and Ankle Outcome Score (FAOS) when used to evaluate the outcome of 213 patients (mean age 40 years, 85 females) who underwent anatomical reconstruction of the lateral ankle ligaments with an average postoperative follow-up of 12 years (range, three to 24 years). The FAOS is a 42-item questionnaire assessing patient-relevant outcomes in five separate subscales (Pain, Other Symptoms, Activities of Daily Living, Sport and Recreation Function, Foot- and Ankle-Related Quality of Life). The FAOS met set criteria of validity and reliability. The FAOS appears to be useful for the evaluation of patient-relevant outcomes related to ankle reconstruction.

The development and validation of the ROwan Foot Pain Assessment Questionnaire (ROFPAQ) is described. This is the first attempt to develop a multi-dimensional measure of chronic foot pain, and recognizes pain as having sensory, affective and cognitive dimensions. The ROFPAQ was developed from themes that emerged from running focus groups and semi-structured interviews with people with chronic foot pain. Following piloting and selection of appropriate items by both psychometric and semantic means, the scale was found to meet the accepted criteria for validity and reliability. The final scale demonstrates better than standard readability, has a short completion time and a simple scoring method. The scale allows clinicians to determine which dimension(s) of foot pain are the most relevant to the subject, thereby aiding decisions regarding appropriate treatment. Topics for further work on the ROFPAQ are highlighted.

More than 40 million individuals participate in organized baseball and softball leagues in the United States every year. Unfortunately, it has also been estimated by the Consumer Product Safety Commission that softball and baseball are the two main sports leading to emergency-room visits in the United States. A previous field study has determined that the utilization of breakaway bases has the potential of preventing 96% of sliding injuries, thereby preventing 1.7 million injuries a year in the United States with a savings of $2 billion a year in health care costs. It is the purpose of this study to analyze and compare the potential attenuating capabilities of various types of bases. We found the force at the ankle upon impact when compared to the standard base revealed all breakaway bases reduced the force of impact to a statistically significant level. The force at the foot upon impact when compared to the standard base revealed all breakaway bases reduced the force at variable levels, with the Rogers bases having the only statistically significant reduction. However, the force delivered to the tibia/fibula was increased with the Stay Down and Mag-Net large bases as compared to the standard stationary base. The moments of inversion/eversion and dorsiflexion/plantar flexion upon impact, when compared to the standard base, revealed all safety bases were reduced to a statistically significant level.

We conclude breakaway bases reduce the force of impact and moments to a statistically significant level and confirm previous field studies. Though there is a difference among the breakaway bases themselves, they should be used on all fields.

The senior author's (R.C.) first 25 patients (37 feet) treated with a combination proximal crescentic osteotomy and distal soft-tissue reconstruction made up the patient cohort. All 25 patients were reviewed at a minimum of one year post-op (short-term follow-up) and 20/25 (31/37 feet) were reviewed again at a mean 12.2 years (range 11.4 to 13.0 yrs) post-op (long-term follow-up). This allowed for a comparison of short- and long-term results and led to a long-term follow-up rate of 84% (31/37 feet, mean 12.2 yrs). Clinical, radiographic and patient outcome measures were obtained and compared pre-op and at short- and long-term follow-up. The mean preoperative hallux valgus (HVA) and intermetatarsal angles (IMA) were 37° and 16° respectively. The mean HVA correction was 24° and IMA correction 10° at long-term follow-up with no tendency toward recurrence. Sesamoid position and first MTP subluxation was markedly improved postoperatively and the correction was maintained at long-term follow-up.

Patients were asked about their satisfaction in terms of pain, appearance and motion. At long-term follow-up, more than 90% of patients were completely satisfied with pain and motion and greater than 80% with their appearance. Ninety-four percent of patients said they would have the operation again. The AOFAS clinical rating scale for the hallux was calculated retrospectively for pre-op and short-term follow-up and prospectively for long-term follow-up. The mean pre-op score was 37/100 (16 to 60) which significantly improved to 92/100 (67 to 100) at both follow-up periods, suggesting no evidence of decrease in outcome over time.

Complications included two patients (5%) that were over-corrected into varus (one symptomatic, one asymptomatic), and four patients (11%) that were undercorrected, developing asymptomatic recurrences (>10° increase HVA) at long-term follow-up. In addition, two patients (5%) developed new transfer lesions postoperatively, likely related to technical error (one varus overcorrection, one dorsiflexion malunion).

In conclusion, the long-term results, with a mean follow-up of 12.2 years, of the resection realignment procedure for moderate to severe hallux valgus are generally excellent and the complication rate is low and acceptable. Attention to detail, avoiding both undercorrection, which can lead to recurrence, and overcorrection, which can cause symptomatic varus, is essential.

Juvenile Hyalin Fibromatosis (JHF) or systemic hyalinosis is a rare, sporadic or hereditary disorder characterized by skin lesions, gingival hypertrophy, muscle weakness, and flexion contractures of large joints. There is still dispute in its pathogenesis and treatment. We described two cases with adult form of Juvenile Hyalin Fibromatosis localized in the foot and discussed the local control we achieved by surgery.

We investigated the most advantageous internal rotation angle of the leg for mortise radiographs. One hundred and twenty-eight feet of 64 healthy volunteers with no histories of ankle or foot pathology (72 feet of 36 males, 56 feet of 28 females) were examined. The subjects had an average age of 29 years (range, 19 to 51 years), average height of 167 cm (range, 157 to 181 cm), and average foot length of 25 cm (range, 23 to 27 cm). We obtained a plain axial view at the level of the central patella and 5 mm proximal to the tibial plafond using computed tomography, and investigated the inclination angle of the distal tibiofibular joint to a horizontal plane, regarding it as a mortise angle. The mean mortise angle was 19.1 + 5.0°. However, two peaks were observed at around 15° and 20°. This indicated that the mean mortise angle of the males was 21.2 + 4.6°, and the mean mortise angle of the females was 16.4 + 4.1°, with a significant difference between the males and the females' mortise angle (P < 0.0001). There was no correlation between the mortise angle and the height (P = 0.899 in the males, and P = 0.871 in the females), nor between the mortise angle and the foot length (P = 0.359 in the males, and P = 0.512 in the females). Therefore, we concluded that the internal rotation angle of the leg for mortise radiography should be generally set up at about 20° on males and 15° on females.

The distal chevron osteotomy is a well-established technique for correction of symptomatic mild to moderate metatarsus primus varus with hallux valgus deformity. Fixation of the osteotomy ranges from none to bone pegs, Kirschner wires, screws, or absorbable pins. We evaluated one surgeon's (J.K.D.) results of distal chevron osteotomy fixation with a single, nonpredrilled, 1.3-mm poly-p-dioxanone pin and analyzed any differences in patients with unilateral or bilateral symptomatic metatarsus primus varus with hallux valgus deformities. All osteotomies healed without evidence of infection, osteolysis, nonunion, or necrosis. Equal correction was achieved in unilateral and bilateral procedures. The technique is quick and easy, and adequate fixation is achieved.