The effect of lateral ankle sprain on dorsiflexion range of motion, posterior talar glide, and joint laxity

STUDY DESIGN: Retrospective study. Objective: Assess range of motion, posterior talar glide, and residual joint laxity following ankle sprain in a population of athletes who have returned to unrestricted activity. BACKGROUND: Lateral ankle sprains occur frequently in athletic populations and the reinjury rate may be as high as 80%. In an effort to better understand risk factors for reinjury, the sequelae to injury in a sample of college athletes were assessed. METHODS AND MEASURES: Twelve athletes with a history of lateral ankle sprain within the last 6 months and who had returned to sport participation were tested. Only athletes who reported never injuring the contralateral ankle were included. The injured and uninjured ankles of subjects were compared for measures of joint laxity, ankle dorsiflexion range of motion, and posterior talar glide. Friedman's test of rank order was used to analyze the laxity measures and a MANOVA was used to assess the dorsiflexion and posterior talar glide measures. RESULTS: Laxity was significantly greater at the talocrural and subtalar joints of the injured ankles. There were no significant differences in any of the ankle dorsiflexion measurements between injured and uninjured ankles, but posterior talar glide was significantly reduced in injured ankles as compared to uninjured ankles. CONCLUSION: In our sample of subjects, residual ligamentous laxity was commonly found following lateral ankle sprain. Dorsiflexion range of motion was restored in the population studied despite evidence of restricted posterior glide of the talocrural joint. Although restoration of physiological range of motion was achieved, residual joint dysfunction persisted. Further research is warranted to elucidate the role of altered arthrokinematics after lateral ankle sprain.     

Instrumented measurement of anteroposterior and inversion-eversion laxity of the normal ankle joint complex

Manual examination is the most common method for the evaluation of ankle anteroposterior (AP) and inversion-eversion (I-E) laxity. Objective assessment data of normal ankle laxity must be provided before comparison with an injured ankle can be made. The purpose of this study was to compare AP translation and I-E rotation at three force loads between dominant and nondominant ankles and to assess the test-retest reliability of a portable arthrometer in obtaining these measurements. The arthrometer consists of a frame that is fixed to the foot, a pad that is attached to the tibia, and a load-measuring handle that is attached to the foot plate through which the load is applied. A six-degrees-of-freedom spatial kinematic linkage system is connected between the tibial pad and the foot frame to measure motion. Instrumented measurement testing of total AP displacement and I-E rotation of both ankles was performed in 41 subjects (21 men and 20 women; mean age, 23.8 +/- 4.4 years). Subjects had no history of ankle injury. Subjects were tested in the supine position while lying on a table with the knee secured in extension and the foot positioned at 0 degrees of flexion. Laxity was measured from total AP displacement (millimeters) during loading to 125 N of AP force and from total I-E rotation (degrees of range of motion) during loading to 4000 N-mm. Reliability was evaluated by calculating intraclass correlation coefficients (2,1) at 75 N, 100 N, and 125 N of AP force and at 2000, 3000, and 4000 N-mm torque loads. Mean differences for displacement and rotation between the dominant and nondominant ankles at each of the force and torque loads were analyzed by dependent t-tests. For both the dominant and nondominant ankles, respectively, the reliability coefficients at each of the force loads for AP displacement (range, 0.82-0.89) and I-E rotation (range, 0.86-0.97) were high. The t-test analyses showed no significant differences (P > or = 0.05) for total AP displacement or I-E rotation between the dominant and nondominant ankles at any of the force loads. The results are clinically useful in providing information about the reliability of measures at different AP and I-E force loads using a portable ankle ligament arthrometer.     

Ligament laxity following inversion injury with and without chronic ankle instability

BACKGROUND: Not all patients develop chronic ankle instability (CAI) after one or more lateral ankle sprains; some seem to heal or adjust to the ankle laxity after injury. Why do some patients develop CAI and others are able to cope and return to normal function? The purpose of this study was to examine ligament laxity between subjects with and without CAI. MATERIALS AND METHODS: Sixteen subjects with unilateral CAI and 16 subjects without participated in the study. Ligament laxity was measured with an instrumented ankle arthrometer. The arthrometer measured ankle joint motion for anterior/posterior displacement (mm) during loading at 125 N and inversion/eversion rotation (degrees of ROM) during loading at 4000 N/mm. For each dependent variable a 2 x 2 mixed model ANOVA was run with the between factor being group (CAI, No CAI) and the within factor with repeated measures being side (involved, uninvolved). RESULTS: A significant group by side interaction for anterior displacement (F(1,30) = 370.085, p < 0.001), and inversion rotation (F(1,30) = 7.455, p = 0.010) was found. There was significantly more anterior displacement and inversion rotation for the involved ankles of the CAI group than the involved ankles of the stable group and the uninvolved ankles of the CAI group. CONCLUSION: Based on the results of this study it appears that the increased anterior displacement and inversion rotation compared to patients without instability may be why subjects develop CAI. Although the patients without instability have a history of more than one lateral ankle sprain, they did not demonstrate increased laxity, which may be the reason why they do not complain of the functional impairment demonstrated in subjects with CAI.     

Ankle ligament injury risk factors: a prospective study of college athletes.

Over two million individuals suffer ankle ligament trauma each year in the United States, more than half of these injuries are severe ligament sprains; however, very little is known about the factors that predispose individuals to these injuries. The purpose of this study was to determine the risk factors associated with ankle injury. We performed a prospective study of 118 Division I collegiate athletes who participated in soccer, lacrosse, or field hockey. Prior to the start of the athletic season, potential ankle injury risk factors were measured, subjects were monitored during the athletic season, and injuries documented. The number of ankle injuries per 1,000 person-days of exposure to sports was 1.6 for the men and 2.2 for the women. There were 13 injuries among the 68 women (19%) and seven injuries among the 50 men (13%), but these proportions were not significantly different. Women who played soccer had a higher incidence of ankle injury than those who played field hockey or lacrosse. Among men, there was no relationship between type of sport and incidence of injury. Factors associated with ankle ligament injury differ for men relative to women. Women with increased tibial varum and calcaneal eversion range of motion are at greater risk of suffering ankle ligament trauma, while men with increased talar tilt are at greater risk. Generalized joint laxity, strength, postural stability, and muscle reaction time were unrelated to injury.     

Natural history of multiple hereditary osteochondromatosis of the lower extremity and ankle.

In this study the authors evaluated the natural history of the ankle joint in patients with multiple hereditary osteochondromatosis. Thirty-eight subjects with an average age of 42 years completed a detailed subjective questionnaire and underwent clinical and radiographic evaluation of their ankles. Three subjects (8%) indicated their ankle involvement affected their vocation, and 12 (32%) were limited in recreational sports. Seven patients (18%) had pain in at least one ankle on a weekly basis, with an average ankle pain score of 2.2. Ankle range of motion averaged 50 degrees and subtalar motion was considered normal in two thirds of ankles. Radiographic evaluation documented an average tibiotalar tilt of 9 degrees of ankle valgus, with evidence of degenerative joint disease noted in 14 ankles (19%). Those with arthritic changes had significantly more tibiotalar tilt and diminished ankle range of motion compared with those without radiographic signs of osteoarthritis. These findings document measurable decreases in ankle function and suggest that correction or prevention of excessive tibiotalar tilt may be warranted to improve outcome.     

Lack of Definition of Chronic Ankle Instability With Arthrometer-Assisted Ankle Joint Stress Testing: A Systematic Review of In Vivo Studies

Despite extensive research on ankle instability a consensual and clear objective definition for pathological mechanical lateral ankle instability is yet to be determined. This systematic review aimed to summarize current available arthrometric devices, measuring methods and lateral ankle laxity outcomes in patients with chronic ankle instability that underwent objective arthrometric stress measurement. Sixty-eight studies comprising a total of 3,235 ankles with chronic ankle instability were included. Studies reported a wide range of arthrometric devices, testing position and procedures, and measuring methods. For the anterior drawer test, the average mean differences between injured and uninjured ankles ranged from -0.9 to 4.1 mm, and total translation in the injured ankle from 3.2 to 21.0 mm. Most common pathological threshold was ≥4 mm or ≥10 mm unilaterally and ≥3 mm bilaterally. For the talar tilt test, the average mean differences between injured and uninjured ankles ranged from 0.0° to 8.0°, and total tilt from injured ankle from 3.3 to 60.2°. Most common pathological threshold was ≥ 10° unilaterally and ≥ 6° mm bilaterally. It was found high heterogeneity in the scientific literature regarding the arthrometric devices, use of concomitant imaging and measuring methods of arthrometer-assisted anterior drawer and talar tilt tests which led to variable laxity outcomes in individuals with chronic ankle instability. Future studies should focus on standardizing the testing and measuring methods for an objective definition of mechanical ankle instability.     

Lateral rotatory dislocation of the ankle without fracture

A 34-year-old woman sustained a closed lateral rotatory dislocation of the ankle without a fracture. Treatment was by closed reduction and cast immobilization for 6 weeks. After removal of the cast, her ankle was stable. Stress radiographs of both the affected and contralateral ankles were normal. One year after injury the patient demonstrated a full, pain-free, stable range of motion. The patient exhibited generalized ligamentous laxity, which may have contributed to her tendency to dislocate the talus within the mortise.     

Sagittal Ankle and Midfoot Range of Motion Before and After Revision Total Ankle Replacement: A Retrospective Comparative Analysis

The most common reason for a revision total ankle replacement procedure is a painful, stiff ankle even after the initial surgery. Limited and conflicting data are available regarding the change in sagittal foot and ankle range of motion after revision total ankle replacement surgery. We sought to determine whether revision total ankle replacements would reduce compensatory midfoot range of motion. In determining this, a novel radiographic measurement system with stable osseous landmarks is used. A retrospective medical record review of patients who had undergone revision total ankle replacement from January 2009 to June 2016 was performed. Thirty-three patients (33 ankles) underwent revision total ankle replacement surgery and met the inclusion criteria with a mean follow-up period of 28.39?±?14.68 (range 2 to 59) months. Investigation of preoperative and postoperative weightbearing lateral radiographic images was performed to determine the global foot and ankle, isolated ankle, and isolated midfoot sagittal ranges of motion. Statistical analysis revealed a significant increase in ankle range of motion (p = .046) and a significant decrease in midfoot range of motion (p < .001) from preoperatively to postoperatively. The change in global foot and ankle range of motion was not significant (p = .53). For this patient population, the increased ankle range of motion effectively resulted in less compensatory midfoot range of motion.     

The relationship between chronic ankle instability and variations in mortise anatomy and impingement spurs

Thirty-five patients undergoing a Br?strom procedure for ankle instability were studied retrospectively as to the presence or absence of spurs and loose bodies, outcome, and mortise relationships. 100 adult volunteers had their ankles radiographically and clinically examined for spurs, loose bodies, and laxity. 100 patients' ankles with computed axial tomography were examined to define malleolar relationships. The AOFAS Hindfoot scores on the Br?strom patients with or without spurs were not different. Patients undergoing a Br?strom procedure had a 3.37 times incidence of spurs and/or loose bodies compared to normal adult population. The incidence of asymmetric but asymptomatic ankle laxity in normal adults was 11%. The fibula has a 38 degree range of position relative to the axis of the talus and the medial malleolus. A posterior fibular position may predispose to injury.     

The Achilles Tendon in Healthy Subjects: An Anthropometric and Ultrasound Mapping Study

Ultrasonography is an inexpensive, fast, and reliable imaging technique widely used to assess the Achilles tendon. Although significant data exists regarding pathologic tendon changes, ultrasound data from healthy individuals are more limited. We aimed to better characterize ultrasound Achilles tendon measurements in healthy individuals and identify important correlating factors. The information collected included patient demographics, body habitus, activity level, foot dominance, and resting ankle angle. Ultrasound analysis was performed bilaterally on the Achilles tendons of 50 subjects using a high-frequency transducer to measure tendon width, thickness, cross-sectional area, and length. Males had a significantly larger mean tendon length, width, thickness, and cross-sectional area. No statistically significant difference was found in any tendon dimension between the white and black participants. Similarly, no difference was found in any tendon parameter when comparing right versus left leg dominance. Healthy subjects had a mean ankle resting angle of 45.1° ± 24° with no statistically significant difference between right and left ankles. Considering all individuals, each tendon parameter (tendon length, width, thickness, and cross-sectional area) correlated positively with subject height, weight, tibia length, and foot size. Only the Achilles cross-sectional area correlated significantly with the activity level. The resting angle of the ankle correlated positively with both tendon length and thickness. In conclusion, we found significant variations in Achilles tendon anatomy in the healthy adult population. We have thoroughly characterized significant correlations between healthy tendon dimensions and various body habitus, activity levels, and ankle parameters. Greater knowledge of the normal Achilles tendon anatomy and characterization of its variations in the healthy population will potentially allow for better pathologic diagnosis and surgical repair.     

"Normal" talar tilt angle.

A study to determine the degree of normal talar tilt in individuals with no history of ankle injuries was performed on 404 ankles of 202 midshipmen at the U.S. Naval Academy. Manual inversion stress roentgenograms were used to test this group of young healthy adults, most of whom were males. Of the 404 ankles tested, only 39 (9.7%) had any measurable talar tilt and only 7 ankles (1.7%) had a tilt over 5 degrees. Normal talar tilt does not range to 23 degrees. A normal ankle in a healthy young adult with no history of trauma has a small probability of having any talar tilt. When stress roentgenograms are used to evaluate a fresh lateral ankle ligament sprain in this type of individual, there is a very high probability that talar tilt over 5 degrees would represent significant injury to one or more of the lateral supporting structures.     

Fixation of syndesmotic ruptures in 38 patients with a malleolar fracture: a randomized study comparing a metallic and a bioabsorbable screw

OBJECTIVES: To compare the performance of a metallic and a biodegradable screw in the fixation of tibia-fibula syndesmotic ruptures. DESIGN: A randomized, prospective, and blinded study. SETTING: Central hospital, Department of Surgery. PATIENTS: Forty consecutive patients with a clinically verified syndesmotic rupture in association with a malleolar fracture, of whom 38 completed the study. INTERVENTION: After syndesmosis rupture was diagnosed, implant selection was performed intraoperatively by a strict randomization with sealed envelopes. Eighteen patients were treated with a metallic screw, and 20 with a bioabsorbable polylevolactic acid screw. The metallic screws were removed in a second operation at 8 weeks postoperatively. All patients had a treatment-blinded clinical and radiographic control after a mean follow-up of 35 (range 17-51) months. MAIN OUTCOME MEASURES: Return to previous physical activity level, evaluation of ankle stability, range of motion, circumference of the ankle, and a radiographic evaluation of both ankles including a measure of the talocrural, medial joint, and syndesmotic space widths. RESULTS: More patients with a polylevolactic acid screw returned to their previous activity level, and there was less swelling in the ankles of these patients, but joint motion was similar between the groups. The mean values of syndesmotic and medial joint spaces were significantly higher in the radiographs of the operated ankles when compared to the uninjured ankle, but there was not a correlation to the type of screw used. CONCLUSIONS: Polylevolactic acid screws worked as well, or slightly better than, metallic ones in syndesmosis fixation in patients with an ankle fracture.     

Ankle joint complex mobility of children 7 to 14 years old.

The ranges of motions of the ankle have been studied only rarely in children. The authors examined the mobility of the ankle joint complex of 245 healthy children. The mean age was 10.2 years. In healthy children ages 7 to 14 years, the variation of the ankle joint complex range of motion was wide. The largest gender-related difference was recorded for passive plantarflexion, which was greater in girls. Other statistically significant gender differences do exist, but they are small and probably lack clinical meaning. Some of the children had remarkable left-right difference in the range of motions of the ankle joint complex. This means that the "healthy ankle" cannot necessarily be used in clinical practice as a reference when evaluating, for example, treatments of foot and ankle injuries in children.     

Reconstruction of the lateral ankle ligaments using a split peroneus brevis tendon graft

Thirty-one consecutive ankles in 30 patients with chronic lateral ankle instability were reconstructed using a split peroneus brevis tendon graft. All patients had pain and instability despite adequate treatment and a rehabilitation program. Six patients had clinical and radiographic evidence of associated subtalar laxity. Four patients (four ankles) had prior Brostrom ligament reconstructions. The average time from the initial injury or treatment to surgery was 23 months. At a mean follow-up of 44 months (range, 24-64 months), the functional results included excellent in 20 ankles, good in 9, fair in 1, and poor in 1. Ankle stability, which did not deteriorate with time, was achieved in 30 of 31 ankles. This procedure is simple, safe, and reliable with a 94% good to excellent clinical result and 97% mechanical stability. It is an excellent reconstruction choice for those individuals with high demand ankles, with a longstanding ankle instability with or without subtalar instability, and for failed primary reconstruction.     

Ankle arthrodesis using dowel bone graft and cancellous-bone screwsA mechanical study in cadavers

Background?There are numerous techniques for ankle arthrodesis. Material and methods?We studied the stability of an ankle arthrodesis with the use of two cross-screws combined with dowel graft technique in 14 fresh-frozen ankles from amputees. The arthrodesis was performed by a dowel graft technique, in the coronal plane in 7 specimens (group 1) and in the diagonal plane in the remaining 7 (group 2). Allocation into the two groups took place after normalization according to the bone mineral content of the specimens. All ankles were fixed with two 6.5-mm diameter cancellous-bone screws, with the ankle in neutral position. Tibiotalar motion was measured during 5 Nm torque loading in plantar flexion-dorsiflexion, abduction-adduction and eversion-inversion planes of the ankle joint. Two testing sequences were performed and the mean value of both tests in each direction was used for the analysis. Results?In all 3 planes, the torque applied caused more motion with the dowel graft in the coronal plane (group 1) than with the graft in the diagonal plane (group 2). The differences between the two groups were significant for abduction-adduction and eversion-inversion planes. Statistical analysis of differences between the first and second test showed significantly greater stiffness in group 2 than in group 1 in plantar flexiondorsiflexion torque. Interpretation?The placement of a dowel graft in the diagonal plane in comparison to the coronal plane significantly increased the initial stability of an ankle arthrodesis.     

Knee joint proprioception in normal volunteers and patients with anterior cruciate ligament tears,taking special account of the effect of a knee bandage

Proprioception of the knee joint was tested in 30 healthy volunteers with clinically inconspicuous knee joints. To examine proprioception, an angle reproduction test was performed. We could not document any differences between the left and the right knee joint or between men and women. At the mid-range, proprioception was worse compared with the end range of motion. In addition, 25 patients with an isolated rupture of the anterior cruciate ligament were evaluated, 14 before and 11 after operative anterior cruciate ligament (ACL) reconstruction. Preoperatively, there was a significant deterioration of proprioception compared with the control group. We were able to show a positive influence of a knee bandage on the proprioception of the injured knee. Patients after ACL reconstruction showed no significantly better proprioception compared with the preoperative group.     

Anatomic reconstruction of the lateral ligaments of the ankle using a plantaris tendon graft

The purpose of this work was to present our technique of anatomic reconstruction of the lateral ankle ligaments using a free plantaris tendon graft. Between 1988 and 1997, 52 ankles (48 patients) were treated for chronic ankle instability resisting to a training program of minimally 3 months. The average age was 28.6 years (16 to 46 years) at the time of surgery. There were 30 ankles in men and 22 ankles in females. 4 patients were treated on both ankles. 50 ankles were available for a follow-up investigation after a mean of 3.5 years (1 to 10 years). Based on the AOFAS-Hindfoot-Scale an average score of 97.9 points (90 to 100 points) was found. The functional result was found to be excellent in 39 ankles (78 %), good in 9 ankles (18 %), fair in 2 ankles (4 %), and poor in 0 ankle (0 %). Dorsi-/plantarflexion was not restricted in any ankle. Supination was slightly restricted in 2 ankles, but not increased in any ankle. High patient's satisfaction with respect to the achieved stability was found in all but one ankle. No deterioration with time was observed in any case. The overall good and excellent results with this method may be explained by the strictly anatomic reconstruction that did not alter the kinematics nor the mechanics of the ankle joint complex. In addition the peroneal tendons were not weakened. We feel that this procedure is a better alternative to other more complex ligament reconstructions, especially tenodesis operations by using the peroneal tendon.     

Balance training for persons with functionally unstable ankles.

STUDY DESIGN: A nonrandomized 2-group pretest-posttest design. OBJECTIVES: To determine the effects of a 4-week balance training program during stance on a single leg. BACKGROUND: Individuals who have experienced multiple episodes of inversion ankle sprains often participate in balance training programs. Balance training is performed to treat existing proprioceptive deficits and to restore ankle joint stability, presumably by retraining altered afferent neuromuscular pathways. The effectiveness of such programs on individuals with functionally unstable ankles has yet to be established. METHODS AND MEASURES: Prior to and following training, subjects with self-reported functionally unstable ankles (5 women and 8 men, mean age = 21.9 +/- 3.1 years) and nonimpaired subjects (6 women and 7 men, mean age = 21.2 +/- 2.5 years) completed a static balance assessment for both limbs as well as the ankle joint functional assessment tool questionnaire (AJFAT). The subjects from both groups participated in a unilateral, multilevel, static and dynamic balance training program 3 times a week for 4 weeks. Subjects from the experimental group trained only the involved limb, and the nonimpaired group trained a randomly selected limb. A stability index (SI) was calculated during the balance assessment to indicate the amount of platform motion. Compared to low stability indices, high stability indices indicate greater platform motion during stance and therefore less stability. RESULTS: Following training, subjects from both groups demonstrated significant improvements in balance ability. When balance was assessed at a low resistance to platform tilt (stability level 2), the posttraining scores of both the subjects with unstable ankles (mean SI = 2.63 +/- 1.92) and the nonimpaired subjects (mean SI = 2.69 +/- 2.32) were significantly better than their pretraining scores (mean SIs = 5.93 +/- 3.65 and 4.67 +/- 3.43, respectively). Assessed at a high resistance to platform tilt (stability level 6), the posttraining scores of both subjects with unstable ankles (mean SI = 1.27 +/- 0.66) and the nonimpaired subjects (mean SI = 1.37 +/- 0.66) were significantly better than their pretraining scores (mean SIs = 2.30 +/- 1.88 and 2.04 +/- 1.43, respectively). Additionally, the posttraining AJFAT scores of subjects with unstable ankles (25.78 +/- 3.80) and the nonimpaired subjects (29.15 +/- 5.27) were significantly greater than their pretraining scores (17.11 +/- 3.44 and 22.92 +/- 5.22, respectively), indicating an overall improvement in perceived ankle joint functional stability. CONCLUSIONS: This study suggests that balance training is an effective means of improving joint proprioception and single-leg standing ability in subjects with unstable and nonimpaired ankles.     

Kinematics of a total arthroplasty of the ankle: comparison to normal ankle motion

Although the concept of a total ankle arthroplasty has been advanced as a method for treating severe ankle arthritis, the clinical experience with all of the models developed has been discouraging. Both the constrained designs, which maximize joint contact area by restricting the available motion, and the unconstrained designs, which allow more normal motion at the expense of higher contact stresses, uniformly result in implant loosening, pain, and clinical failure in 2 to 7 years. This has led to the recommendation against the use of a total ankle arthroplasty except in very low-demand patients. Failure of ankle implants can be ascribed to either anatomic considerations (e.g.--the talus is too small to accommodate the stress transfers of a prosthesis), or mechanical etiologies. Abnormal 3-dimensional motion of the ankle following arthroplasty would fall into the latter category. This study examined the motion that occurs after implantation of an unconstrained-type total ankle arthroplasty. Using previously validated methodology, axially loaded ankle specimens were cycled through an arc of plantarflex/dorsiflexion while measuring the resulting coupled internal/external and varus/valgus rotations. The average coupled motions in prosthetic ankles were not significantly different than their intact controls. There was, however, a significantly increased amount of hysteresis (defined as the difference between the upper and lower pathways of coupled motion at any given sagittal position) that occurred as the ankle was dorsiflexed and plantar flexed. The increased hysteresis was seen in both the axial and coronal planes. This indicates that there was a greater permitted envelop of motion in the prosthetic ankles compared to normal ankles. It is hypothesized that this subtle change in ankle kinematics caused by the arthroplasty leads to abnormal stress transfer at the prosthesis-bone interface, thereby promoting early implant failure.     

Treatment of lateral ankle instability with transfer of the extensor digitorum brevis muscle

Ankle sprains are the most common injuries sustained during sports and physical exercise. Treatment is usually conservative because most of these injuries heal without consequence. However, some injuries may be followed by chronic lateral pain and instability, and surgical stabilization is sometimes necessary. In select cases, there is little or no residual ligament or scar tissue remaining for late reconstruction. Proximal transfer of the origin of the extensor digitorum brevis muscle as a substitute for deficient ligament tissue can be used in these difficult cases. During the years 1971 to 1992, 13 ankles in 10 patients underwent surgery using the proximal extensor digitorum brevis muscle transfer method. At follow-up, all the ankles manifested functional stability and were stable with no clinical drawer sign. All had a normal range of motion in the ankle joint but showed a desired decreased supination range of motion throughout the hindfoot and ankle. The functional Karlsson scores were 84.5 +/- 18.8 before injury, 26.4 +/- 18.7 before surgery, and 83.6 +/- 18.7 at follow-up. Thus, the extensor digitorum brevis muscle transfer seems to be a useful alternative method of long-term ankle stabilization in these difficult chronic case; the results correlate well with a few other studies using this method.