Contribution of the anterolateral joint capsule to the mechanical stability of the ankle

Published reports describe the clinical efficacy of modified Brostrom anatomic repairs, surgical procedures that involve repair and fortification of the lateral capsuloligamentous complex of the ankle for patients suffering from chronic lateral instability of this joint. A cadaveric serial sectioning study of the anterior talofibular ligament, the calcaneofibular ligament, and the remainder of the anterolateral joint capsule was completed to quantitate the contribution of the superior portion of the anterolateral joint capsule, independent of the other two structures, to the overall mechanical stability of the lateral ankle. Using 20 fresh frozen specimens, talar tilt and anterior drawer stress radiographs were taken before and after sectioning these anatomic structures in an order established by one of two protocols. Sectioning of the superior anterolateral joint capsule caused 17% to 18% of the total displacement in a Grade II sprain simulation and 29% to 33% of the total displacement in a Grade III sprain simulation. This work suggests that disruption of the segment of ankle joint capsule superior to the anterior talofibular ligament creates approximately 30% of the overall laxity encountered in a Grade III inversion sprain, substantiating the principle of restoring the integrity of the entire anterolateral joint capsule when operating on a chronically unstable ankle.     

Arthroscopic treatment of soft-tissue impingement of the ankle in athletes

Sixty ankle arthroscopies were performed on patients with chronic soft-tissue impingement of the ankle after an ankle sprain between January 1989 and January 1994. Preoperative examination findings featured tenderness localized to the anterolateral aspect of the ankle, no instability, and, with the exception of 2 patients, normal radiographs. A preoperative bone scan was performed on 34 patients and was positive in each case but was not specific. Arthroscopy was performed an average of 23 months after injury. Results were determined by using a new ankle rating score. Hypertrophic synovium, synovitis, or fibrous adhesions were arthroscopically visualized and resected in all cases. The average follow-up was 27 months (range, 6 to 64 months). Thirty-one patients underwent complete evaluation and 29 were evaluated over the telephone. There were 51 excellent, 7 good, 1 fair, and 1 poor results. The diagnosis of chronic soft-tissue impingement of the ankle can be made from an appropriate history, thorough physical examination, and plain radiographs. Ankle arthroscopy with resection of impinging hypertrophic synovium or fibrous bands occurring after an ankle sprain was effective in alleviating pain in athletes.     

Acute inversion injury of the ankle: magnetic resonance imaging and clinical outcomes

This study was undertaken to compare the clinical and magnetic resonance imaging results of 24 patients who had sustained ligament injuries after acute inversion injury of the ankle. On magnetic resonance imaging, the following lesions were detected: anterior talofibular ligament tear in 23 patients, calcaneofibular ligament lesion in 15, posterior talofibular ligament lesion in 11, interosseous talocalcaneal ligament lesion in 13, cervical ligament lesion in 12, and deltoid ligament lesion in 8. Compared with the clinical outcome at the follow-up study, there was a statistically significant relationship between interosseous talocalcaneal ligament lesion and each of giving way, pain, and limitation of ankle motion; between cervical ligament lesion and both giving way and pain; and between deltoid ligament lesion and giving way (P < 0.05).     

Midline osteotomy with lag screw stabilization for mandibular swing

Fifteen patients with recurrent inversion ankle sprains and documented lateral ankle instability were treated with an anatomically oriented ligament reconstruction using a split peroneus brevis tendon graft. This reconstruction is designed to augment repair of the anterior talofibular and calcaneofibular ligaments without restricting subtalar motion. Of the 12 patients available for long-term followup, all were functionally improved, with no recurrences of instability. Stress radiographic examination at followup confirmed that mechanical stability had been restored in all ankles. Eversion strength and subtalar joint motion were maintained after surgery. We recommend this procedure in patients who require augmented reconstruction of the lateral ankle ligaments.     

Evaluation and diagnosis of ankle injuries

The evaluation of ankle injuries is a common challenge for family physicians. Diagnosis is made by using knowledge of the anatomy and function of the ankle joint to aid in taking an adequate history and performing an appropriate physical examination. The patient should be questioned about the mechanism of injury, previous injury, disability, treatment and pain. The ankle should be evaluated for ecchymosis, swelling, areas of tenderness and laxity. These measures help to determine what, if any, additional diagnostic procedures may be needed. Most ankle sprains are lateral, affecting the anterior talofibular, calcaneofibular and posterior talofibular ligaments. Other injuries include medial ankle sprains affecting the deltoid ligament, trauma to the Achilles and peroneal tendons, tarsal tunnel syndrome, fractures, syndesmotic sprains, synovial impingement and chronic instability. Criteria for radiographic evaluation include inability to bear weight initially or when examined, and tenderness over the medial or lateral malleolus. Accurate diagnosis is critical for appropriate treatment and minimizing functional disability.     

Ligaments of the ankle: normal anatomy with MR arthrography

PURPOSE: Our purpose was to define the normal MR arthrographic anatomy of ankle ligaments. METHOD: Prior to injection of intraarticular gadolinium in cadaveric ankle joints, proton density and T2-weighted images were obtained to assess the integrity of the ligaments and tendons as well as the amount of preexisting joint effusion. Following injection of 10 ml of contrast agent (gadopentetate dimeglumine 1:250, Omnipaqe 300, Knox gelatin 50%, and methylene blue), T1-weighted images with fat saturation in axial, oblique axial, coronal, and sagittal planes were obtained in neutral, dorsiflexion, and plantar flexion positions. Specimens were sectioned, allowing anatomic and MR correlation. RESULTS: Contrast agent outlining anterior and posterior aspects of the anterior talofibular ligament and posterior talofibular ligament (PTAF) was a normal finding, related to anterior and posterior recesses of the ankle joint that extend out beyond these ligaments in an anteroposterior direction above the level of the ligaments. Intraarticular contrast material allowed resolution of superficial and deep components of the posterior tibiofibular ligament. Both were seen separately from PTAF with dorsiflexion. Posterior intermalleolar ligament was not present in our specimens. Visualization of calcaneofibular ligament was much improved by contrast material outlining the articular aspect of the ligament. Visualization of the syndesmotic ligamentous complex also was improved by contrast material outlining the articular side of the ligaments and separating them from adjacent bone. Superiorly, the distribution of contrast agent was limited by the interosseous ligament. Visualization of the medial collateral ligaments was not improved by the presence of the intraarticular contrast material. CONCLUSION: MR arthrography of the ankle allows improved visualization and evaluation of the lateral and syndesmotic ligamentous complex.     

Arthroscopy for problems after ankle fracture

From 1990 to 1994 we undertook arthroscopy of the ankle on 34 consecutive patients with residual complaints following fracture. Two groups were compared prospectively. Group I comprised 18 patients with complaints which could be attributed clinically to anterior bony or soft-tissue impingement. In group II the complaints of the 16 patients were more diffuse and despite extensive investigation the definitive diagnosis was not clear before arthroscopy. At the time of the fracture, some osteophytes were already present in 41% of the patients. These were related to previous supination trauma and participation in soccer. Arthroscopic treatment consisted of removal of the anteriorly located osteophytes and/or scar tissue. After two years, group I showed a significantly better score for patient satisfaction (p = 0.02). There were good or excellent results in group I in 76% and group II in 43%. Patients with residual complaints after an ankle fracture and clinical signs of anterior impingement may benefit from arthroscopic surgery. The place for diagnostic ankle arthroscopy is limited.     

Biomechanical comparison of reconstruction techniques in simulated lateral ankle ligament injury

Eighteen intact ankles were loaded with inversion-eversion and anterior-posterior forces, and motions of the talus and calcaneus were measured. Ankles were tested in neutral, 15 degrees of dorsiflexion, and 15 degrees of plantar flexion. The anterior talofibular ligament was then sectioned and testing was repeated. In half the specimens the calcaneofibular ligament was also sectioned followed by repeat testing. The Evans, Watson-Jones, and Chrisman-Snook procedures were performed on each ankle and testing was repeated. With inversion-eversion loading, only the Chrisman-Snook reconstruction resulted in a significantly more stable ankle joint complex than in the anterior talofibular ligament cut ankles. All three reconstructions increased ankle stability over the anterior talofibular and calcaneofibular ligament cut state. With anterior-posterior loading, all reconstructions resulted in a significantly more stable ankle joint complex than the anterior talofibular ligament cut ankles. The Evans and Chrisman-Snook procedures resulted in more stability than the anterior talofibular and calcaneofibular ligament cut ankles. There was no difference in subtalar joint motion with inversion-eversion loading among ankles with the anterior talofibular ligament cut and those with any of the reconstructions. For the anterior talofibular and calcaneofibular ligament cut ankles, subtalar joint motion was similar to that in intact ankles after each reconstruction. All three reconstructions resulted in ankles with significantly less subtalar joint motion with anterior-posterior loading than ankles with the anterior talofibular ligament cut or with the anterior talofibular and calcaneofibular ligaments cut. The Chrisman-Snook procedure resulted in ankles with significantly less motion than intact ankles.     

Arthroscopic treatment of anterior ankle impingement

Ankle arthroscopy has recently allowed the elaboration of less invasive techniques for the treatment of anterior impingement. Its indications, advantages, and drawbacks in this application are discussed. Between 1987 and 1994, 133 patients were treated for ankle impingement. Among them, 58 patients, 37 men and 21 women (mean age, 28.5 years), who had failed a trial of conservative treatment were treated by means of tibiotalar arthroscopy. Twenty-seven were athletes engaged in sports with abnormal stressing of the ankle. According to McDermott's radiological classification, there were 15 stage I cases, 23 stage II, 13 stage III, and 7 stage IV. Preoperative evaluation with a modified version of McGuire's scoring system gave 50 cases rated as "poor" (< 60 points) and 8 cases rated as "fair" (60-67 points). Treatment consisted of removal of adhesions, cartilage shaving, and removal of the bone impingement with powered instruments, curettes, or small osteotomes. Follow-up was from 8 to 62 months (mean, 21.5 months). The postoperative McGuire ratings were 37 good, 13 fair, and 8 poor. There were no major complications. Recurrence of impingement was observed in four cases of stage III and IV. The conclusion is drawn that ankle arthroscopy is a sound method for the treatment of anterior impingement. Even in cases with severe joint cartilage impairment, it plays a therapeutic role as a means of postponing a possible arthrodesis.     

Subtalar arthrography in acute injuries of the calcaneofibular ligament

We treated 43 acute tears of the calcaneofibular ligament by operation in 43 patients after subtalar arthrography. There were 22 men and 21 women with a mean age of 22.3 years (14 to 61). Anteroposterior (AP), lateral and oblique views were obtained with the foot in 45 degrees of internal rotation and the ankle in the neutral position. Any communication or leakage to the ankle, tendon sheaths, subcutaneous tissue and sinus tarsi was recorded. We examined an oblique view of the microrecess along the interosseous ligament and an AP view of the lateral recess just under the distal end of the fibula. We also studied a control group of 27 patients with isolated injuries of the anterior talofibular ligament without rupture of the calcaneofibular ligament. The findings in the two groups were significantly different when examined for leakage to the ankle (p=0.0002), to the peroneal tendon sheaths (p=0.0347) and to the subcutaneous tissue (p=0.0222), absence of the microrecess (p=0.0055) and presence of the lateral recess (p=0.0012). Many ankle sprains which involve tearing of the calcaneofibular ligament are accompanied by injuries of the subtalar joint. Combined injuries of the anterior talofibular ligament and calcaneofibular ligament, and isolated injury of the anterior talofibular ligament should be differentiated.     

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OBJECTIVE: The primary role of the anterior cruciate ligament is to resist anterior subluxation of the tibia. When the ligament is torn, the tibia is free to sublux anteriorly when the leg is pulled forward. In addition to visualizing the anterior cruciate ligament directly, MR imaging can show joint alignment. The purpose of this study was to test the efficacy of MR images of anterior subluxation of the tibia for diagnosing complete tears of the anterior cruciate ligament. MATERIALS AND METHODS: We evaluated the records of 120 consecutive patients who underwent MR imaging of the knee and subsequently had arthroscopy. Arthroscopy showed a complete tear of the anterior cruciate ligament in 21 patients, a partial tear in eight patients, and an intact anterior cruciate ligament in 91 patients. Two radiologists together reviewed the MR images, and interpretation of anterior cruciate ligament integrity was reached by consensus. The anterior cruciate ligament was categorized as intact, completely torn, or partially torn on the basis of conventional MR imaging criteria. The degree of anterior subluxation of the tibia was measured on a separate occasion in random order by a radiologist who used a sagittal section through the middle of the lateral femoral condyle. On the selected image, two vertical lines parallel to the left and right margins of the image frame were drawn tangent to the posterior cortical margins of the lateral femoral and tibial condyles. Anterior subluxation of the tibia was determined by the distance in millimeters between these two lines and measured with calipers by using the 5-cm scale on the images. Measurements were considered reliable only to one half of the smallest increment of this scale (i.e., 5 mm). Accordingly, tibial subluxation (x) was measured in 5-mm increments, with x < or = 0 mm designated grade 0, 0 mm < x < or = 5 mm designated grade 1, 5 mm < x < or = 10 mm designated grade 2, and so forth. RESULTS: Conventional MR imaging criteria had 90% sensitivity and 94% specificity for diagnosing complete tears of the anterior cruciate ligament. According to the receiver-operating-characteristic (ROC) curve, anterior subluxation of the tibia greater than 5 mm (grade 2 or greater) was considered to be the optimal threshold (sensitivity, 86%; specificity, 99%) for diagnosing complete tears of the anterior cruciate ligament. Notably, none of the six false-positive diagnoses of complete tears by conventional criteria (three partial tears and three intact ligaments at arthroscopy) were misdiagnosed when tibial subluxation was used as the diagnostic criterion. Subluxation greater than 5 mm can be falsely negative with chronic tears of the anterior cruciate ligament (n = 2) or when a displaced bucket-handle tear of the lateral meniscus blocks anterior subluxation of the tibia (n = 1). CONCLUSION: An anterior tibial subluxation greater than 5 mm (grade 2 or greater) is a simple objective measurement that serves as a helpful adjunctive sign in the diagnosis of complete tears of the anterior cruciate ligament. This sign also offers improved discrimination of complete from partial tears of the anterior cruciate ligament.     

Ligament injuries of the ankle--what happens later? Non-surgical treatment is effective in 80-90 per cent of cases

Ligament injuries of the ankle joint are the most common sports-related injuries. In more than 90 per cent of all cases, it is a question of lateral ligament injury. The recommended acute treatment is always non-surgical, with range of motion training, followed by strengthening and co-ordination exercises. Approximately 80-90 per cent of all ligament injury patients regain normal ankle function after this form of treatment. Early active treatment can reduce time off from sports and the duration of sick leave. Residual problems, mainly pain or recurrent or chronic instability are seen in approximately 10-20 per cent of cases. In cases of chronic instability, ligament reconstruction is recommended. In patients with anterior or anterolateral ankle pain, arthroscopic resection of bone spurs or loose bodies may be beneficial.     

Value of arthrography after supination trauma of the ankle

OBJECTIVE: To investigate the merits of arthrography after supination trauma of the ankle. DESIGN AND PATIENTS: In a group of 160 consecutive patients operative exploration was performed in cases where arthrography and/or a delayed physical examination showed positive findings. In all patients arthrography was performed within 48 h after trauma. To determine interobserver agreement, all arthrograms were independently evaluated by two radiologists, both ignorant of the first assessment. RESULTS: The prevalence of an ankle ligament lesion was found to be 76%. Of the 122 patients with a rupture of one or more ankle ligaments, 52% had an isolated anterior talofibular ligament lesion, 3% had an isolated calcaneofibular ligament lesion, and 45% had combined lesions. The site of the lesion was predominantly intraligamentous. In the determination of the presence or absence of an ankle ligament lesion, the specificity and sensitivity of the ankle arthrogram were 71% and 96% respectively. Interobserver agreement on the arthrogram was very good (kappa 0.9). In 1% of patients a clear diagnosis was not possible by means of arthrography. CONCLUSION: Arthrography provides information of high diagnostic quality with excellent interobserver agreement and therefore remains the gold standard for early diagnosis (within 48 h) of a lateral ankle ligament rupture.     

Diagnostic value of MR arthrography in detection of intrinsic carpal ligament lesions: use of cine-MR arthrography as a new approach

Twenty-five patients with chronic wrist pain and a preliminary diagnosis of carpal instability were examined with conventional MR imaging and MR arthrography with single compartment intra-articular injection. A new cine-MR arthrography technique, with image acquisition at every 5 s during intra-articular injection, was performed in 17 subjects. The purpose of this study was to determine the diagnostic value of MR arthrography in ligamentous lesions of the wrist and to assess the value of cine-MR arthrography in comparison with arthroscopy and/or surgery. Magnetic resonance arthrography, a semi-invasive technique, increased the diagnostic accuracy of intrinsic carpal ligament injuries. Cine-MR arthrography can be considered as a promising technique especially for the evaluation of lunatotriquetral and scapholunate ligament injuries of the wrist.     

Effect of chronic hypoxemia on the regulation of nitric-oxide synthase in the fetal sheep brain

We undertook a prospective study to determine the type and distribution of foot and ankle snowboarding injuries. Reports of 3213 snowboarding injuries were collected from 12 Colorado ski resorts between 1988 and 1995. Of these, 491 (15.3%) were ankle injuries and 58 (1.8%) were foot injuries. Ankle injuries included 216 (44%) fractures and 255 (52%) sprains. Thirty-three (57%) of the foot injuries were fractures and 16 (28%) were sprains. The remaining injuries were soft tissue injuries, contusions, or abrasions. There was no significant correlation between boot type (soft, hybrid, or hard) and overall foot or ankle injury rate. There were significantly fewer ankle sprains in patients wearing hybrid boots and fewer fractures of the lateral process of the talus in patients wearing soft boots. An unexpectedly high number of fractures of the lateral process of the talus were noted. These 74 fractures represented 2.3% of all snowboarding injuries, 15% of all ankle injuries, and 34% of the ankle fractures. Many of these fractures are not visible on plain radiographs and require computed tomography imaging to be diagnosed. Diagnosis of this fracture pattern is paramount; the physician should be very suspicious of anterolateral ankle pain in the snowboarder, where subtle fractures that may require surgical intervention can be confused with anterior talofibular ligament sprains.     

Chronic external instability of the ankle. Contribution of dynamic radiographies, x-ray computed tomography and x-ray computed tomographic arthrography

We retrospectively evaluated the anterior talo fibular ligament and the tarsal sinus of 17 patients who had complained of chronic ankle external instability. This study based on both surgery and CT-arthrography findings shows the pathologic or normal aspects of the talo-fibular anterior ligament (normal, lax, fibrosis residue, ruptured). It confirms the good anatomic analysis of the tarsal sinus, in particular the anterior talo-calcaneal interosseous ligament and the search for fibrosis. We underline that capsular distension due to subtalar laxity is not detected with medical imaging. Compared with surgery (all patients), CT arthrography demonstrated the different aspects of the anterior talo fibular ligament injuries (normal, lax, discontinuous).     

Arthroscopic stabilization of the ankle

Arthroscopic lateral ankle stabilization is a method for repair of the anterior talofibular ligament which involves decreased morbidity and minimal soft tissue disruption while restoring function and stability to the joint. This technique utilizes soft tissue anchoring systems that reinforce or repair the anterior talofibular ligament. Several techniques are described for the various types of ligamentous injuries. These methods are compared and contrasted with standard open reconstructive and reparative techniques. Advantages of the newer anchoring systems are discussed.     

The MR appearance of the infrapatellar plica

OBJECTIVE: Our purpose is to describe the MR appearance and clinical relevance of the infrapatellar plica of the knee and to assess possible imaging pitfalls resulting from lack of recognition of this normal structure. Seven patients--four from our institution and three from our teaching file from outside institutions--were selected because they displayed the imaging features of the infrapatellar plica. CONCLUSION: The infrapatellar plica is readily appreciated on sagittal MR images of the knee as a low-signal-intensity structure in the intercondylar notch just anterior to the anterior cruciate ligament (ACL). The infrapatellar plica is important to recognize for the following reasons: It may be confused with an intact ACL because of its proximity and similar signal characteristics; it may pose difficulty to the arthroscopist when attempting to move instruments from the medial to lateral compartments of the knee; it can block clear visualization of the ACL during arthroscopy; and it can impair retrieval of loose bodies in the intercondylar notch. Familiarity with the infrapatellar plica should allow one to differentiate this normal structure from other structures in the knee and aid in preoperative planning.     

Accuracy of direct signs of tears of the anterior cruciate ligament

OBJECTIVE: To evaluate the accuracy of direct magnetic resonance imaging (MRI) signs of tears of the anterior cruciate ligament. PATIENTS AND METHODS: Over the period April 1991 to February 1994, 92 consecutive MRI studies of the knee were obtained for which arthroscopic data were also available. The MRI studies were retrospectively evaluated for course, continuity, signal intensity, morphologic features, contour and visualization of the anterior cruciate ligament. Arthroscopic findings were correlated with individual primary signs and the overall MRI diagnosis. RESULTS: Among the cases studied were 4 partial and 32 complete tears of the anterior cruciate ligament (as determined by arthroscopy). Because of the low number of partial tears, it was not possible to draw any meaningful conclusions about the MRI diagnosis of this type of tear. For complete tears, the criteria with the highest accuracy were abnormal course of the ligament (96.0%) and high signal intensity (89.3%). The overall diagnostic accuracy of MRI was 98.8%. CONCLUSIONS: The most accurate direct MRI finding in patients with a complete tear of the anterior cruciate ligament was abnormal course of the ligament, followed by abnormally high signal intensity.     

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Contact between an anterior cruciate ligament graft and the intercondylar roof has been termed roof impingement. Grafts with impingement sustain permanent damage, and if the injury is extensive enough, then the graft may fail, causing recurrent instability. This study evaluated two mechanical factors that could be responsible for the graft injury associated with roof impingement: an increase in graft tension or elevated pressures between the graft and the roof, or both. An anterior cruciate ligament reconstruction was performed using an Achilles tendon graft in five fresh-frozen cadaveric knees. Using a six-degree-of-freedom load application system, the anterior displacement of the knee with the native anterior cruciate ligament was restored in the reconstructed knee at a flexion angle of 30 degrees and with an anterior force of 200 N applied. Pressure between the graft and intercondylar roof, graft tension, and flexion angle were measured during passive knee extension for three tibial tunnel placements (anterior, center, and posterior). Intercondylar roof impingement increased the contact pressure between the graft and the roof but had no significant effect on graft tension. Therefore, during passive knee extension, the contact pressure between the anterior cruciate ligament graft and the intercondylar roof is a more likely cause of graft damage than increased graft tension.