Technique for in vivo measurement of the three-dimensional kinematics and laxity characteristics of the ankle joint complex

We introduce here a technique to measure the three-dimensional kinematics and laxity characteristics of the ankle joint complex in vivo. The system consists of an optoelectric, kinematic data acquisition system that is used to measure the motion of the ankle joint complex in response to controlled moments applied through a system of pneumatic actuators. As a first step toward development of the method into a quantitative diagnostic tool for injuries of ankle ligaments, we addressed the following questions: (a) What is the reliability for measurement of range of motion and laxity of the ankle joint complex? (b) Are there significant differences in laxity between the left and right joints of a healthy individual? and (c) Are there significant differences in laxity of the ankle joint complex between men and women? To answer these questions, we performed repeated measures of range of motion and laxity of paired ankles in a population of 18 healthy young individuals. The high intraclass correlation coefficients obtained from the statistical analysis indicate that the new experimental system is highly reliable in measurement of total range of motion and total laxity of the ankle joint complex. We further concluded that, within the statistical power available in our experimental design, there are no significant differences in either range of motion or laxity between left and right ankles of healthy individuals or between men and women.     

Chronic pain after ankle fracture: an arthroscopic assessment case series

BACKGROUND: The purpose of this study was to document findings of ankle arthroscopy in patients with residual complaints after an appropriately treated ankle fracture. METHODS: Patients who had ankle arthroscopy at the Alpine Orthosports Clinic between 1998 and 2000 were identified by a retrospective review of the ankle arthroscopy database. Fifty patients were identified who had arthroscopy for complaints after ankle fracture. The mean duration from injury to arthroscopy was 20.5 +/- 33.5 months, with a range of 2 to 184.6 months. RESULTS: There were 37 isolated fractures and 13 combination fractures. The Danis-Weber classification was used for lateral malleolar fractures. There were five type A, 14 type B, and 11 type C lateral malleolar fractures. RESULTS: Synovitis was present in 46 ankles and was located anterolaterally in 36. Synovitis was noted in 26 of the 30 ankles that had a lateral malleolar fracture. Arthrofibrosis was found in 20 ankles, with anterolateral joint involvement in 16. There was chondral damage noted in 45 ankles, 30 located on the talus and 15 on the tibia. Spurs were found in 15 ankles, and nine had loose bodies or debris. There were two postoperative complications: one patient had bleeding from a portal and the other had an area of paresthesia at the anterolateral portal site. CONCLUSION: Synovitis and chondral damage were more frequent than arthrofibrosis and spurs. Synovitis and arthrofibrosis were found most frequently in the anterolateral aspect of the joint. Also, the higher the lateral malleolar fracture was in relation to the syndesmosis, the higher was the occurrence of talar chondral damage.     

Arthroscopic findings associated with the unstable ankle

Before lateral ankle stabilization, arthroscopic surgery was performed on 54 patients (55 ankles) with chronic ankle instability. All patient charts, x-rays, operative reports, and surgical videotapes were reviewed. A detailed questionnaire was answered by all patients. The study population included 31 males and 23 females, with a mean age of 31 years (range, 14-64 years). The right ankle was involved in 64% of cases. Average follow-up was 9.6 months. Arthroscopic surgery was performed using small joint instrumentation including 30 degrees and 70 degrees 2.7-mm arthroscopes and a 30 degrees 1.9-mm arthroscope. At surgery, 51 ankles (93%) had intra-articular abnormalities including loose bodies (12), synovitis (38), osteochondral lesions of the talus (9), ossicles (14), osteophytes (6), adhesions (8), and chondromalacia (12). The most common arthroscopic procedures were synovectomy, removal of loose bodies and ossicles, excision and drilling of osteochondral lesions, debridement of the lateral gutter, excision of osteophytes, and removal of adhesions and scar tissue. There was a 25% incidence of chondral injuries, which differs considerably from the results of Taga et al., who found chondral injuries in 95% of ankles with lateral instability. Overall, there were excellent or good results in 96% of ankles. The incidence of excellent results was lower in the worker's compensation patients because of a greater incidence of complaints of pain with activity. There was no correlation between the presence of osteochondral lesions or amount of talar tilt and results.     

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.     

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.     

Long-term results of the Chrisman-Snook operation for reconstruction of the lateral ligaments of the ankle

The Chrisman-Snook procedure for instability of the lateral ankle ligaments, first described in 1969, reconstructs the anterior talofibular ligament and the calcaneofibular ligament using one-half of the peroneus brevis tendon, routed through tunnels in the fibula and calcaneus. In the present long-term evaluation of the results of this procedure, forty-eight of sixty ankles, in fifty-seven patients, were assessed after a mean follow-up of ten years (range, four to twenty-four years). The results were excellent in thirty-eight ankles, good in seven, fair in two, and poor in one. The two ankles with a fair result were improved but still had some persistent instability, while the ankle with a poor result (no improvement) was in a patient with generalized ligament laxity. All three patients with a fair or poor result had had a severe reinjury to the ankle. Based on the findings in this study, we concluded that this procedure will restore good long-term function in a high percentage of patients who are disabled by ankle instability due to unhealed or neglected tears of the lateral ligaments.     

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.     

Variations in fibular position, talar length, and anterior talofibular ligament length

BACKGROUND: Proprioceptive deficiencies, peroneal muscle weakness, varus hindfoot, and varus tibial plafond have each been implicated as a predisposing factor in recurrent ankle instability. Another predisposing factor for instability is a position of the fibula posterior to the transverse axis of the talus. This study examined the relationship of fibular position and ankle instability with anatomic dissection and magnetic resonance imaging (MRI). METHODS: Data were obtained from 100 consecutive MRI scans of adult ankles: the malleolar index in degrees and the fibular position anterior or posterior to the anteromedial malleolar plane and relative to the transverse axis of the talus. Twenty cadaver ankles also were studied by MRI and then by anatomic dissection. The malleolar index, the talar length, and the length of the anterior talofibular (ATF) ligament were recorded. RESULTS: The MRI study showed that variation of the malleolar index ranged from 2 to 30 degrees. There was no correlation between the malleolar index and the talar length or the length of the ATF ligament. CONCLUSIONS: There is a bell-shaped curve of variation of the position of the fibula relative to the transverse axis of the talus. An ankle mortise with a more posteriorly positioned fibula has less structural stability and is more susceptible to sprain. Neither talar length nor ATF ligament length correlated with fibular position.     

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.     

A long-term review of a modified Evans procedure

Of 111 primary ankle ligament arthroplasties (modified Evans procedure) performed between 1983 and 1994, we were able to identify 89 patients (94 ankles) for follow-up. All were under 50 years of age. Two had died and one refused to co-operate; 86 patients (91 ankles) were therefore reviewed, 25 by telephone and the remainder by clinical examination with all but three also undergoing radiological review. Of the 91 ankles, 70 had no or very mild pain and 72 had no or rare episodes of instability and when considered together only 59 (65%) had no or mild pain and minimal instability. The results were supported by the Karlsson grading system. Clinical examination showed that 17 of the 66 ankles examined had increased inversion, while 21 had some limitation of inversion. Early degenerative changes were seen in 11 ankles, although only four had subtalar changes. These results show that this procedure does not give universally good clinical results. Patient satisfaction, however, was high with 97.7% being willing to undergo the same procedure if their other ankle became similarly affected.     

Arthroscopic elbow findings: correlation with preoperative radiographic studies.

Correlation between arthroscopic findings and preoperative radiographic studies (plain radiographs and arthrotomograms) was performed in a consecutive series of 37 elbows. Arthrotomograms added significant diagnostic information unavailable from plain radiographs alone, thereby improving the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic efficiency (accuracy) in the evaluation of elbow joint surface changes, marginal spurs, and loose bodies. Arthrotomograms gave 85% accuracy for bone spurs, 89% accuracy for joint surface abnormalities, and 89% accuracy for loose bodies (88% accuracy overall), whereas plain radiographs demonstrated 69% accuracy for bone spurs, 71% accuracy for joint surface abnormalities, and 75% accuracy for loose bodies (72% accuracy overall). The arthrotomograms had 100% sensitivity for loose bodies as well as a 100% negative predictive value for loose bodies. Arthrotomograms are indicated when additional preoperative diagnostic accuracy is necessary. These radiographic studies approached only 90% accuracy, confirming that diagnostic arthroscopy adds additional information.     

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.     

Radiographic indicators of ankle instability: changes with plantarflexion

BACKGROUND: The effect of plantarflexion on radiographic indicators of instability was investigated in matched pairs of stable ankles and unstable ankle fractures with complete deltoid ligament tears to test the hypothesis that differences exist in indicators as a function of either stability or position. The purpose of this study was to determine whether plantarflexion increases radiographic indicators of ankle fracture instability. METHODS: Measurements from 34 patients scheduled for operative treatment of unstable ankle fractures were collected prospectively from normal, stable ankles and the injured, unstable ankles. Instability was defined as a positive fluoroscopic stress examination under anesthesia. Stability and instability and neutral position and plantarflexion were associated with eight radiographic indicators of which five were distances in millimeters and three were binomial (either stable or unstable). RESULTS: Measurements were larger in the unstable ankles than in the normal stable ankles. Plantarflexion was associated with increased distances in stable ankles, and a trend was seen in unstable ankles. Plantarflexion was associated with increased binomial indicators in unstable ankles but not in stable ankles. DISCUSSION: Joint positioning affected measurement of ankle stability: plantarflexion increased the sensitivity of radiographic indicators.     

Laxity and flexibility of the ankle following reconstruction with the Chrisman-Snook procedure

The effect of reconstruction of the anterior talofibular ligament with the Chrisman-Snook procedure on neutral zone laxity (anterior-posterior displacement at low loads) and flexibility (a measure of the nonlinear load-displacement response) of the ankle was investigated in vitro during the anterior drawer test. Neutral zone laxity was defined as the magnitude of anterior-posterior displacement of the ankle joint at ±2.5 N of applied load. The flexibility parameter was defined as the slope of a line between the natural logarithm of the anterior load applied to the ankle and the resulting displacement. After reconstruction with the Chrisman-Snook procedure, the values for neutral zone laxity of the ankle were significantly less than normal at 0° of plantar flexion, whereas the flexibility values were significantly greater than normal. This study revealed that, after the Chrisman-Snook procedure, values for ankle flexibility are not restored to normal even if those for neutral zone laxity are reduced to less than normal. The findings suggest that this nonanatomical reconstruction procedure does not reproduce normal kinematics of the ankle joint. This may help explain some of the adverse clinical reports associated with the Chrisman-Snook reconstruction procedure.     

Congenital Dislocation of the Head of the Radius

Twenty patients with chronic ankle instability were examined radiographically for anterior talar displacement and talar tilting. The examinations were carried out with the ankles untaped and taped, and the taped ankles were examined again after 20 min running. The measurable instability was significantly improved after taping, but after exercise this was seen only for talar tilting. Generally, the best stabilizing effect of taping was obtained in the ankles with the greatest degree of instability. After exercise, all but one of the adhesive taping bandages were loose and were mostly acting as canvas boots, affording the ankle only limited protection.     

Taping the ankle for chronic instability

Twenty patients with chronic ankle instability were examined radiographically for anterior talar displacement and talar tilting. The examinations were carried out with the ankles untaped and taped, and the taped ankles were examined again after 20 min running. The measurable instability was significantly improved after taping, but after exercise this was seen only for talar tilting. Generally, the best stabilizing effect of taping was obtained in the ankles with the greatest degree of instability. After exercise, all but one of the adhesive taping bandages were loose and were mostly acting as canvas boots, affording the ankle only limited protection.     

The distal fascicle of the anterior inferior tibiofibular ligament as a cause of anterolateral ankle impingement: Results of arthroscopic resection

We arthroscopically resected the impinged distal fascicle of the anterior inferior tibiofibular ligament (AIT-FL) in 21 patients (mean age 31 (11-68) years, 14 women) with chronic ankle pain after an ankle sprain. Clinical tests revealed moderate laxity in 2 and severe laxity in another 2, the remaining 17 ankles showing only mild laxity. During arthroscopy, an impinging distal fascicle of the AITFL was found in all cases. Following anterolateral synovectomy, the fascicle was excised. At the follow-up after mean 3 (2-4) years, good-to-excellent results were obtained in 17 patients. 19 patients were satisfied with the procedure and 17 patients returned to their previous level of activity. 2 patients who had mild laxity were graded as poor because of neuromas of the terminal branches of the superficial peroneal nerve. These patients became asymptomatic after an injection of steroids.     

The distal fascicle of the anterior inferior tibio-fibular ligament as a cause of anterolateral ankle impingement: results of arthroscopic resection

We arthroscopically resected the impinged distal fascicle of the anterior inferior tibiofibular ligament (AIT-FL) in 21 patients (mean age 31 (11-68) years, 14 women) with chronic ankle pain after an ankle sprain. Clinical tests revealed moderate laxity in 2 and severe laxity in another 2, the remaining 17 ankles showing only mild laxity. During arthroscopy, an impinging distal fascicle of the AITFL was found in all cases. Following anterolateral synovectomy, the fascicle was excised. At the follow-up after mean 3 (2-4) years, good-to-excellent results were obtained in 17 patients. 19 patients were satisfied with the procedure and 17 patients returned to their previous level of activity. 2 patients who had mild laxity were graded as poor because of neuromas of the terminal branches of the superficial peroneal nerve. These patients became asymptomatic after an injection of steroids.     

The distal fascicle of the anterior inferior tibiofibular ligament as a cause of anterolateral ankle impingement: Results of arthroscopic resection

We arthroscopically resected the impinged distal fascicle of the anterior inferior tibiofibular ligament (AIT-FL) in 21 patients (mean age 31 (11-68) years, 14 women) with chronic ankle pain after an ankle sprain. Clinical tests revealed moderate laxity in 2 and severe laxity in another 2, the remaining 17 ankles showing only mild laxity. During arthroscopy, an impinging distal fascicle of the AITFL was found in all cases. Following anterolateral synovectomy, the fascicle was excised. At the follow-up after mean 3 (2-4) years, good-to-excellent results were obtained in 17 patients. 19 patients were satisfied with the procedure and 17 patients returned to their previous level of activity. 2 patients who had mild laxity were graded as poor because of neuromas of the terminal branches of the superficial peroneal nerve. These patients became asymptomatic after an injection of steroids.     

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.