Stress Radiographical Measurements of Post-Traumatic Knee Instability: A Clinical Study

In a prospective, consecutive, clinical and stress radiographical study, comprising 153 traumatic knee injuries, the value of stress radiographical measurements, gonylaxometry, was studied. Clinical evaluation, gonylaxometry and preoperative evaluation under general anaesthesia were carried out in that order. Then the operative findings were recorded as drawings on standard diagrams. These were used as a basis for evaluation of the preoperative tests. of all the methods evaluated, gonylaxometry was found to provide the most accurate information regarding the knee injury. Very close to this result were the findings under general anaesthesia. Anterior drawer sign was measured gonyl-axometrically when damage to the anterior cruciate ligament was present; posterior drawer meant damage to the posterior cruciate ligament. Partial ruptures of cruciate ligaments did not allow antero-posterior displacements exceeding the critical levels of the test. Small positive medial instability was found with ruptures of profound medial structures, higher values with total rupture of the long superficial collateral band, and still higher values when cruciate ligament ruptures were also present. The predictive values of a positive radio-graphical test were 100 per cent as regards medial instability and 98 per cent for drawer looseness. The predictive values of a negative test were 96 per cent for drawer and 92 per cent for medial instability. These figures are based on the total material. 95 per cent confidence limits are given.     

Anterior displacement. Its effects on instability and radiolucency in total knee replacements

One hundred sixty-nine posterior cruciate condylar knee arthroplasties were evaluated for investigation of the effect of anterior displacement on instability and interface radiolucency in total knee arthroplasty. All knees were followed for at least one year, and 37 knees were followed for at least three years. The status of the anterior cruciate ligament at surgery was first compared to the postoperative, six-month, one-year, and three-year anterior drawer sign. A correlation coefficient was computed to test for the existence of a relation between these two variables. A chi-square test for statistical significance was used to compare the overall anterior drawer results with time and the anterior drawer sign at each follow-up evaluation with pain and radiolucent zones between cement and bone. For further evaluation of the effect of anterior stability on radiolucent zones, the authors analyzed the records of all their posterior cruciate condylar total knee arthroplasties over a seven-year period (average follow-up period, 2.5 years). Anterior stability over time was independent of the status of the anterior cruciate at surgery, and the presence or absence of an anterior cruciate ligament at surgery did not affect anterior stability over time. Furthermore, cutting of the anterior cruciate did not change anterior stability over time. Anterior instability proved to be statistically less at six months than at surgery and did not become worse with time. Neither anterior instability nor the preoperative state of the anterior cruciate ligament affects pain and interface radiolucency between cement and bone.     

The course of differently treated isolated ruptures of the anterior cruciate ligament as observed by prospective stress radiography

In a prospective stress radiographic study of the course of 21 isolated anterior cruciate ligament (ACL) injuries, primary suture was performed in eight patients and reconstruction due to chronic instability was performed in six patients. Seven patients were treated by exploratory arthrotomy only. After a follow-up period of seven years the anterior drawer sign had disappeared in five of the 14 patients who had shown this sign prior to operation, but in some of these patients progressive rotatory instabilities developed, so that the total abnormal instability did not improve in any of the three therapeutic groups. Only ten patients obtained a completely symptom-free knee. A well performed Jones procedure could reduce a chronic anterior drawer instability, but in several of the patients troublesome patellofemoral pain developed later. Acute suture of isolated anterior cruciate ligament injuries afforded the best results in this series and is recommended.     

Radiographic instability of the ankle joint after Evans' repair

Forty-two unstable ankle joints were treated surgically by Evans' operation. The clinical postoperative results were correlated with the objective radiological stress examinations. The mean age of the patients was 29 years (15-60 years). The clinical and radiological follow-up examinations were performed 6 months after the operation. In the stress X-ray examinations a modified stress frame was used. Clinical instability was noted in four patients. In the radiological examination one patient had a pathological finding in the talar tilt test and 18 patients in the anterior drawer sign test. The radiological instability correlated poorly with the subjective end results. Six patients were estimated to have a poor result of the operation. Five of these patients had a positive anterior drawer sign in the stress X-ray examination and one had degenerative changes in the ankle. Although Evans' repair is a simple and reliable method of reconstructing ruptures of the lateral ligaments of the ankle joint, it is associated with a relatively high frequency of positive anterior subluxation on radiological stress examination. This finding can be explained by the anatomical and geometrical factors on the lateral side of the ankle joint.     

Radiographic Instability of the Ankle Joint After Evans' Repair

Forty-two unstable ankle joints were treated surgically by Evans' operation. the clinical postoperative results were correlated with the objective radiological stress examinations. the mean age of the patients was 29 years (15-60 years). the clinical and radiological follow-up examinations were performed 6 months after the operation. in the stress X-ray examinations a modified stress frame was used. Clinical instability was noted in four patients. in the radiological examination one patient had a pathological finding in the talar tilt test and 18 patients in the anterior drawer sign test. the radiological instability correlated poorly with the subjective end results. Six patients were estimated to have a poor result of the operation. Five of these patients had a positive anterior drawer sign in the stress X-ray examination and one had degenerative changes in the ankle. Although Evans' repair is a simple and reliable method of reconstructing ruptures of the lateral ligaments of the ankle joint, it is associated with a relatively high frequency of positive anterior subluxation on radiological stress examination. This finding can be explained by the anatomical and geometrical factors on the lateral side of the ankle joint.     

Radiographic Instability of the Ankle Joint After Evans' Repair

Forty-two unstable ankle joints were treated surgically by Evans' operation. the clinical postoperative results were correlated with the objective radiological stress examinations. the mean age of the patients was 29 years (15-60 years). the clinical and radiological follow-up examinations were performed 6 months after the operation. in the stress X-ray examinations a modified stress frame was used. Clinical instability was noted in four patients. in the radiological examination one patient had a pathological finding in the talar tilt test and 18 patients in the anterior drawer sign test. the radiological instability correlated poorly with the subjective end results. Six patients were estimated to have a poor result of the operation. Five of these patients had a positive anterior drawer sign in the stress X-ray examination and one had degenerative changes in the ankle. Although Evans' repair is a simple and reliable method of reconstructing ruptures of the lateral ligaments of the ankle joint, it is associated with a relatively high frequency of positive anterior subluxation on radiological stress examination. This finding can be explained by the anatomical and geometrical factors on the lateral side of the ankle joint.     

Stability tests in knee ligament injuries

For 182 knee joints with ligamentous injuries confirmed at surgery the records contained a complete and documented stability examination. In anterior cruciate ligament injuries the Lachman test and the anterior drawer sign were of similar value with regard to the frequency of false negatives - they missed half of the injuries - but their accuracy improved when they were repeated under anesthesia. The pivot shift was useful only under anesthesia. The medial collateral ligament injuries were usually detected because of valgus instability, also without anesthesia. The stability tests done with the patient under anesthesia are sufficiently reliable for making decisions about knee ligament surgery.     

Partial Rupture of the Anterior Cruciate Ligament

The anterior cruciate ligament (ACL) consists of two major fiber bundles, namely the anteromedial (AM) and posterolateral (PL) bundles. Although disagreement exists among arthroscopic surgeons about the occurrence of isolated ruptures of the AM or PL bundle, there are reports of partial ruptures of the ACL in the literature. A potential reason for controversy could be that with conventional magnetic resonance imaging, isolated PL ruptures are difficult to diagnose because of the oblique course of this bundle. Another reason could be that isolated ruptures of the AM or PL bundle are difficult to diagnose during arthroscopy. During arthroscopy, an isolated PL bundle rupture can easily be missed when viewing from the standard anterolateral portal. The AM bundle overlies the PL bundle, and the PL bundle can only be seen by retraction of the AM bundle with a probe. When the knee is extended, the PL bundle is tight and the AM bundle is moderately lax. As the knee is flexed, the femoral attachment of the ACL becomes horizontally oriented, causing the AM bundle to tighten and the PL bundle to relax. Whereas the AM bundle is the primary restraint against anterior tibial translation in flexion, the PL bundle tends to stabilize the knee near full extension, particularly against rotatory loads. The different bundle contributions to knee stability in the flexed or extended positions can aid in the diagnosis of partial ACL ruptures. Isolated rupture of the AM bundle has more effect on the anterior drawer sign than on the Lachman test, whereas the converse is true for isolated rupture of the PL bundle. Rotational instability as a result of PL bundle rupture can be tested with the pivot-shift test. Pivot shift can be negative in cases with isolated AM bundle rupture. If only one bundle of the ACL is torn, isolated AM or PL bundle reconstruction should be considered. Although potentially difficult, a careful diagnostic evaluation is necessary before ACL surgery.     

Diagnostic and incidence of the rupture of the posterior cruciate ligament

The purpose of this article is to evaluate the incidence and to give a general review of the examination of the posterior ligament complex. At least ca. 8–10 % of all severe ligament injuries concern the posterior cruciate ligament, which means, that an estimated 4000–5000 Germans suffer a PCL rupture every year. Motor-vehicle accidents are the most common cause of the injury, but sports-related traumas (football, skiing) have increased in recent years. The high number of high-energy mechanisms involved (up to 90 %), cause ligament ruptures often to be associated with other injuries, especially fractures of the femur and tibia head. In polytrauma patients PCL ruptures are frequently recognized very late, because the possibility of this kind of injury is often not considered during the clinical examination. The same holds for the diagnosis of monotrauma patients. The initial step in the evaluation is to obtain a thorough history (including the mechanism of injury) and to perform a physical examination. The instability after a PCL rupture may present as an ACL rupture, because the anterior drawer test seems to be positive. The anterior/posterior drawer test must be assessed with other evaluation procedures to distinguish between anterior und posterior instabilities. The posterior sag sign, the quadriceps active test or the reversed pivot-shift may indicate a PCL rupture. A correct roentgenogram can reveal an avulsion of the tibia and can prove posterior instability due to a posterior translation of the tibia. A quantitative examination (clinical or X-ray) of the instability and the indication of combined injury of the posterior cruciate ligament and the posterolateral complex are necessary for the therapeutic decision (operative/conservative). A rupture of the PCL may occur occasionally as a result of a luxation of the knee (reduced spontaneously) before the medical evaluation. A thorough neurovascular examination is essential. Magnetic resonance imaging can be important to the diagnosis of an acute injury, but it is not essential for the choice between operative and non-operative treatment. Arthroscopy has been found to have a high degree of accuracy in the diagnosis of ligament ruptures of the knee, but it is still an operative treatment, so that it can only be used if an operation of repair or reconstruction is planned anyway. Before operative treatment of chronic complex instability, potential osseous abnormalities (varus morphotype) must be revealed; in case of uncertainty, an X-ray control is necessary.     

Diagnostic and incidence of the rupture of the posterior cruciate ligament

Summary The purpose of this article is to evaluate the incidence and to give a general review of the examination of the posterior ligament complex. At least ca. 8–10 % of all severe ligament injuries concern the posterior cruciate ligament, which means, that an estimated 4000–5000 Germans suffer a PCL rupture every year. Motor-vehicle accidents are the most common cause of the injury, but sports-related traumas (football, skiing) have increased in recent years. The high number of high-energy mechanisms involved (up to 90 %), cause ligament ruptures often to be associated with other injuries, especially fractures of the femur and tibia head. In polytrauma patients PCL ruptures are frequently recognized very late, because the possibility of this kind of injury is often not considered during the clinical examination. The same holds for the diagnosis of monotrauma patients. The initial step in the evaluation is to obtain a thorough history (including the mechanism of injury) and to perform a physical examination. The instability after a PCL rupture may present as an ACL rupture, because the anterior drawer test seems to be positive. The anterior/posterior drawer test must be assessed with other evaluation procedures to distinguish between anterior und posterior instabilities. The posterior sag sign, the quadriceps active test or the reversed pivot-shift may indicate a PCL rupture. A correct roentgenogram can reveal an avulsion of the tibia and can prove posterior instability due to a posterior translation of the tibia. A quantitative examination (clinical or X-ray) of the instability and the indication of combined injury of the posterior cruciate ligament and the posterolateral complex are necessary for the therapeutic decision (operative/conservative). A rupture of the PCL may occur occasionally as a result of a luxation of the knee (reduced spontaneously) before the medical evaluation. A thorough neurovascular examination is essential. Magnetic resonance imaging can be important to the diagnosis of an acute injury, but it is not essential for the choice between operative and non-operative treatment. Arthroscopy has been found to have a high degree of accuracy in the diagnosis of ligament ruptures of the knee, but it is still an operative treatment, so that it can only be used if an operation of repair or reconstruction is planned anyway. Before operative treatment of chronic complex instability, potential osseous abnormalities (varus morphotype) must be revealed; in case of uncertainty, an X-ray control is necessary.      

Stability tests in knee ligament injuries

Summary For 182 knee joints with ligamentous injuries confirmed at surgery the records contained a complete and documented stability examination. In anterior cruciate ligament injuries the Lachman test and the anterior drawer sign were of similar value with regard to the frequency of false negatives — they missed half of the injuries — but their accuracy improved when they were repeated under anesthesia. The pivot shift was useful only under anesthesia. The medial collateral ligament injuries were usually detected because of valgus instability, also without anesthesia. The stability tests done with the patient under anesthesia are sufficiently reliable for making decisions about knee ligament surgery.     

The anterior cruciate ligament. A functional analysis based on postmortem studies.

In forty fresh human cadaver knees the function of the anterior cruciate ligament and of its two component parts, the posterolateral part and the anteromedial band, were studied by cutting these ligaments and others in different sequences and combinations and then manually stressing the knees. The anterior drawer sign cannot be obtained unless the anteromedial band is severed. The postolateral part and the medial collateral ligament are, respectively, the secondary and tertiary restraints limiting the anterior drawer sign. Both internal and external rotation are limited by the anterior cruciate ligament, especially when the knee is in extension. The anterior cruciate ligament also limits hyperextension.     

Anterior cruciate ligament insufficiency treated by combined medial and lateral extra-articular reconstruction

Thirty patients who required surgery for an unstable knee with "giving way" symptoms were operated during 1979-1981 with a pes anserinus transfer and an Ellison procedure at the same séance. All patients had an insufficient anterior cruciate ligament prior to surgery. Of these 24 patients had a positive pivot-shift test, and 26 patients had an anteromedial rotatory instability. Twenty-eight patients were seen at a follow-up after an average of 28 months (range 19-49). There were 12 women and 16 men, with a mean age of 28 years. Eleven patients (39%) declared that their knee function was distinctly improved, and six (21%) that it was moderately improved after surgery. Knee function was unchanged for ten patients (36%), and one patient said that the knee function had deteriorated after surgery. The functional result was not correlated with the duration of symptoms or with the follow-up time. Physical examination revealed that the anterior drawer had not disappeared for any of the patients. A positive pivot-shift sign was still present in 18 patients, and 23 patients displayed an increased varus instability.--All but six patients still had some instability experiences, and most of them could not completely return to active sports. However, the method could provide an alternative for patients engaged in frequent but not heavy physical activity.     

Evaluation of knee instability in acute ligamentous injuries

The stability on clinical examination (CE) and examination under anaesthesia (EUA) was evaluated in 350 consecutive acute knee injuries. Valgus instability in knees with a medial collateral tear was observed on CE in 62 and on EUA in 67 cases (p less than 0.05). The anterior drawer sign was positive in 55 patients on CE and in 110 patients on EUA (p less than 0.0001), the corresponding figures for the Lachman test were 66 and 126 respectively (p less than 0.0001). The pivot shift-test was positive in 13 cases on CE and in 87 under anaesthesia (p less than 0.0001). Fresh total tears of the anterior cruciate ligament (confirmed at arthrotomy, n = 79) were detected by the Lachman test in 48 per cent on CE and in 96 per cent on EUA. Of the nine fresh, total tears of the posterior cruciate ligament three were disclosed by the posterior drawer test on CE and all nine on EUA. Anteromedial rotatory instability was observed on CE in 10 patients and on EUA in 47 (p less than 0.0001). In these patients 41 medial collateral tears, 23 posteromedial capsular tears, 21 medial meniscus and 40 anterior cruciate lesions were found. On CE only one anterolateral rotatory instability was found, whereas EUA disclosed 9 cases. Posteromedial rotatory instability was not confirmed on CE, though on EUA four cases were found. CE and EUA detected 2 and 3 posterolateral instabilities respectively. In conclusion, the use of EUA with an adequate mode of stability evaluation in acute knee injuries is strongly advocated. Clinical examination is considered highly unreliable with many false negative findings.     

Clinical diagnosis of ruptures of the anterior cruciate ligament: a comparison between the Lachman test and the anterior drawer sign

A comparative study of the diagnostic accuracy between the Lachman test and the anterior drawer test was performed by examining 144 knees with ruptured anterior cruciate ligaments.

The diagnosis of anterior cruciate ligament rupture is often difficult to establish, especially in recent injuries with acute haemarthrosis.

The diagnostic accuracy of the Lachman test in recent ruptures when the patient is examined without general anaesthetic is superior to that of the anterior drawer test, while in chronic cases with third-degree instability the two tests are equally reliable.     

Chronic lateral instability of the ankle. Roentgen stereophotogrammetry of talar position

Using roentgen stereophotogrammetric analysis (RSA), we investigated the talar mobility in 54 ankles during the anterior drawer and adduction tests. Talar tilt was increased in ankles with unilateral symptoms of chronic lateral instability. No other difference in talar tilt and anterior drawer sign was noted comparing ankles with and without symptoms. We conclude that mechanical tests cannot always verify the diagnosis "chronic lateral instability of the ankle".     

Demonstration of Rotatory Instability in Injured Knees by Stress Radiography

Rotatory instability of injured knees may be demonstrated by stress radiography by recording the different movements of the medial and lateral tibial condyle at pull or push with the knee in 90 degrees flexion. The displacements of the condyles are expressed in millimetres, not degrees. Comparison with the healthy knee is always used. The displacement of a tibial condyle has to exceed 3.0 mm in relation to the healthy knee to be defined as pathological. If the movements of both condyles exceed the movements in the healthy knee by more than 3.0 mm in the same direction a drawer sign is present - if only one of them moves, an abnormal rotation is present. When a drawer sign is present there may still be a greater displacement of one of the tibial condyles which means a rotatory instability added to the drawer sign, designated a complex rotatory instability. All types of rotatory instabilities, simple and complex, are defined and discussed, in relation to the classification of Nicholas, Trickey and Slocum & Larson. Forty-one cases of abnormal rotation were demonstrated in this series by stress radiography. The direction of rotation and the type of instability are described and compared with the operative findings. The findings are in agreement with those of the above-mentioned authors and the experimental work of Warren et al.     

关节镜下应用Rigidfix与Intrafix系统固定异体肌腱重建前交叉韧带

目的 探讨关节镜下应用Rigidfix与Intrafix系统固定同种异体胫前肌肌腱重建前交叉韧带(ACL)的临床效果. 方法自2003年3月至2006年9月对56例在关节镜下确诊ACL断裂的患者采用深低温同种异体胫前肌肌腱进行韧带重建,应用Rigidfix与Intrafix系统对移植物进行固定,术后进行系统康复训练.随访观察患者的主观症状,并检查患膝关节活动度、前抽屉试验、Lachman试验和轴移试验,按照Lysholm膝关节评分标准评价疗效.结果 所有患者随访1.5～5.0年,平均2.3年.有2例患者在剧烈活动时伴有错动感,末次随访时膝关节活动度均可达到伸-5°～0°,屈120°～130°,前抽屉试验、Lachman试验及轴移试验均为阴性,Lysholm膝关节评分由术前(48.2±5.3)分提高至术后(91.1±4.2)分,差异有统计学意义(P<0.05).结论 关节镜下应用Rigidfix与Intrafix系统固定同种异体胫前肌肌腱重建ACL可获得满意的临床疗效.     

Chronic lateral instability of the ankle Roentgen stereophotogrammetry of talar position

Using roentgen stereophotogrammetric analysis (RSA), we investigated the talar mobility in 54 ankles during the anterior drawer and adduction tests. Talar tilt was increased in ankles with unilateral symptoms of chronic lateral instability. No other difference in talar tilt and anterior drawer sign was noted comparing ankles with and without symptoms.

We conclude that mechanical tests cannot always verify the diagnosis “chronic lateral instability of the ankle “.     

Dynamic musculotendinous transfer to replace the anterior cruciate ligament in the dog

Dynamic muscle-tendon substitution for acute anterior cruciate deficiency in the dog was studied using the semimembranosus muscle-tendon. Nineteen mongrel dogs each had a semimembranosus transfer in one knee; as a control, the anterior cruciate ligament and the semimembranosus were released in the opposite knee. No postoperative immobilisation was used. The anterior drawer sign was assessed before and after operation and when the dogs were killed five months later. Dogs were excluded from the study if they developed infections or contractures of the hind legs. At five months, 11 dogs were available for study. The operated knees were examined histologically and evaluated using a reproducible index of arthritis based on: the macroscopic discoloration of the articular cartilage, the cellularity of the cartilage, the microscopic appearance of the articular surface, the loss of proteoglycans, the formation of osteophytes and the degree of subchondral osteosclerosis. There was no significant difference in the anterior drawer sign or the degree of arthritic changes between knees with a semimembranous transfer and the controls. Examination showed that a muscle-tendon transfer into the tibia was equivalent to transferring the muscle into the posterior capsule--the intra-articular tendon being weak but histologically viable. The transfer did not prevent the anterior drawer sign becoming positive nor the development of osteoarthritis. A second control group, in which three dogs had an arthrotomy and semimembranosus release in both their hind legs, showed that a semimembranosus release alone did not cause osteoarthritis.