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.     

Diagnosis of acute knee ligament injuries: the value of stress radiography compared with clinical examination, stability under anaesthesia and arthroscopic or operative findings

A consecutive series of 85 stress radiographic examinations was performed in order to evaluate the clinical reliability and use of stress radiography in disclosing acute knee ligament injuries. Eighty-three examinations were performed within one week of the injury. Sagittal stress examination discovered 27% of the 37 anterior cruciate ligament (ACL) tears and all four posterior cruciate tears. Valgus stress detected 56% of the medial collateral tears. The specificity of stress radiography was even reduced by the number of false positive stress results (n = 25) in posterior drawer or valgus-varus examinations. An ACL tear was, however, an isolated or major ligament injury in twenty (80%) of the false positive results. Clinical examination revealed all the medial collateral tears whereas only 40% of the anterior cruciate tears. The most reliable method for diagnosing acute knee injuries where clinical examination has failed in disclosing instability is examination under anaesthesia supplemented by acute arthroscopy.     

应力后沉征诊断单纯后交叉韧带损伤

目的　对 18例经手术证实为急性单纯后交叉韧带损伤行应力下胫骨后移的定量分析 ,以评价应力后沉征在诊断后交叉韧带损伤中的作用。方法　术前在麻醉和屈膝 90°行双膝应力 (15kg)下的摄片并定量分析 ,得出双膝应力前后的胫骨后移情况。结果　患膝较健侧有明显的胫骨后移 ,患膝应力下平均胫骨后移较非应力下提高 1+级。结论　在诊断急性后交叉韧带损伤时 ,麻醉下和屈膝 90°位应力后沉征较后沉征和后抽屉试验准确和灵敏 ,应力摄片示胫骨后移有明显意义的升高。要理解屈膝 90°位和麻醉下行后沉征和后抽屈试验的重要性     

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.     

Partial rupture of the anterior cruciate ligament. Natural course

A prospective study was done of 29 patients with conservatively treated partial ruptures of the anterior cruciate ligament that were stable at the initial examination under anesthesia. The ruptures were reevaluated for stability and knee function from 12 to 60 months after injury. Many had developed signs of instability. The forward drawer sign (Lachman test) and the pivot shift tests were positive. There was also measurable sagittal instability (anterior drawer sign). In every case, knee function was almost completely restored.     

Arthroscopy in acute knee injuries

The diagnostic value of arthroscopy was evaluated in 148 patients with acute hemarthrosis and/or instability of the knee. The treatment planned after clinical examination was compared with the treatment given after arthroscopy. Seventy-nine per cent of the patients had ligamentous injuries; 59 per cent of tears were combined with other injuries, and 71 per cent were complete ruptures. Stability testing under anesthesia was most inaccurate for the anterior cruciate ligament, with 13 per cent false positive and 30 per cent false negative results. The planned treatment was altered as a consequence of arthroscopy in 31 per cent of cases. Without arthroscopy, the preoperative diagnoses would have been seriously wrong in 15 per cent of the patients. Twenty per cent of total anterior cruciate ligament ruptures would have been overlooked.     

Experimental Analysis of the Quadriceps Muscle Force and Patello-Femoral Joint Reaction Force for Various Activities

The diagnostic value of arthroscopy was evaluated in 148 patients with acute hemarthrosis and/or instability of the knee. The treatment planned after clinical examination was compared with the treatment given after arthroscopy. Seventy-nine per cent of the patients had ligamentous injuries; 59 per cent of tears were combined with other injuries, and 71 per cent were complete ruptures. Stability testing under anesthesia was most inaccurate for the anterior cruciate ligament, with 13 per cent false positive and 30 per cent false negative results. The planned treatment was altered as a consequence of arthroscopy in 31 per cent of cases. Without arthroscopy, the preoperative diagnoses would have been seriously wrong in 15 per cent of the patients. Twenty per cent of total anterior cruciate ligament ruptures would have been overlooked.     

Arthroscopy in acute knee injuries

The diagnostic value of arthroscopy was evaluated in 148 patients with acute hemarthrosis and/or instability of the knee. The treatment planned after clinical examination was compared with the treatment given after arthroscopy. Seventy-nine per cent of the patients had ligamentous injuries; 59 per cent of tears were combined with other injuries, and 71 per cent were complete ruptures. Stability testing under anesthesia was most inaccurate for the anterior cruciate ligament, with 13 per cent false positive and 30 per cent false negative results. The planned treatment was altered as a consequence of arthroscopy in 31 per cent of cases. Without arthroscopy, the preoperative diagnoses would have been seriously wrong in 15 per cent of the patients. Twenty per cent of total anterior cruciate ligament ruptures would have been overlooked.     

The accuracy of selective magnetic resonance imaging compared with the findings of arthroscopy of the knee

The results of selective magnetic resonance imaging of the knee were compared with those of arthroscopy in a prospective series of fifty patients. A specifically designed protocol for imaging, producing T1 sagittal images interleaved at four millimeters while the patient's foot was in 20 degrees of external rotation, was utilized. This technique, called selective magnetic resonance imaging, yielded excellent visualization of the posterior cruciate ligament, medial meniscus, and lateral meniscus in all patients. However, in only 76 per cent of the patients was the anterior cruciate ligament well visualized. Compared with arthroscopy, the sensitivity, specificity, and accuracy of selective magnetic resonance imaging were, respectively, 95.8, 100, and 98 per cent for tears of the medial meniscus; 66.7, 95.1, and 90 per cent for tears of the lateral meniscus; undefined, 100, and 100 per cent for tears of the posterior cruciate ligament; and 100, 96.9, and 97.3 per cent for tears of the anterior cruciate ligament, when that ligament was well visualized. Our selective sequence can be performed in fifteen minutes at a cost that is comparable with that of arthrography. It is totally non-invasive and requires no exposure to ionizing radiation. Selective magnetic resonance imaging can be a safe and valuable adjunct to the clinical evaluation of the knee and an aid to efficient preoperative planning.     

A clinical and stress radiographical follow-up investigation after Jones' operation for replacing the anterior cruciate ligament

Measurements have been made on knee radiographs exposed during stress displacement by controlled hydraulic forces using a specially designed apparatus. This accurately records the amount of anterior and posterior tibial displacement (drawer sign) and the degree of medial and lateral collateral ligament laxity on radiographs. The findings in 25 patients have been analysed following the Jones' procedure for the repair of the anterior cruciate ligaments.The operative results were judged to be completely successful in 72 per cent of patients and the value of stress radiographic measurements is discussed.     

Diagnosis of anterior cruciate ligament injury of the knee joint]

From January, 1979 to May, 1989, 107 patients with problems related to anterior cruciate ligament (ACL) were treated in our hospital. 100 of the patients had anterior cruciate ligament injury confirmed by arthrotomy or arthroscopy. The remaining 7 patients were found to be normal either by arthroscopy or arthrotomy. 29 patients had fresh ACL injury and 71 old. All the patients had history of trauma of the knee joint. Swelling and pain in the affected knee joint took place in fresh cases and few of them complained of instability or deformity of the knee. On examination, floating patella test was positive in the majority of the fresh cases. It was shown that accurate diagnosis could be made by Lachman test rather than by conventional anterior drawer test in dealing with fresh injury, but with old ones, Lachman test didn't show the advantages. Examination under anesthesia or arthroscopy helped a lot in diagnosing fresh ACL injury. Anterior drawer test (ADT) was significant in determining the existence of ACL injury. When ADT was positive, ACL injury was found in the majority of the cases, however, injured ACL couldn't be ruled out by negative ADT only. Positive valgus stress test on 0 degrees position suggests possibility of ACL injury, even ADT was negative. Despite the negative anterior drawer test positive posterior drawer test on three directions indicated the injury of the posterior cruciate ligament and the anterior cruciate ligament. The positive rate of ADT was higher than that of pivot shift test in dealing with anterior cruciate ligament injury. Positive pivot shift test suggests ACL injury.     

The locked knee

Fifty patients presenting themselves with a locked knee were investigated prospectively by examination under anaesthesia and arthroscopy. Definite abnormality was found in 92 per cent. Torn menisci were present in 68 per cent and isolated ruptures of the cruciate ligament in 10 per cent. Loose bodies were found in 3 patients, degenerative changes alone in 2 patients and a pathological medial synovial shelf in 1 patient. No abnormality was demonstrated in 8 per cent. Sixteen per cent of the knees remained locked following the induction of anaesthesia. This study demonstrates that a true mechanical block is not necessarily present and that the position of an unstable meniscal fragment is not consistently related to the fixed position of the knee under anaesthetic. There were no clinical features that allowed the normal knees to be distinguished preoperatively from those with internal derangement. It is proposed that these patients should be managed by prompt examination under anaesthesia, arthroscopy and definitive 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.      

Posterior instability of the knee near extension. A clinical and stress radiographic analysis of acute injuries of the posterior cruciate ligament

We evaluated the accuracy of six clinical tests for posterior instability in 24 knees with acute surgically-proven posterior cruciate ligament injuries and intact anterior cruciate ligaments. We also performed stress radiography under anaesthesia. The gravity sign and the posterior drawer test in near extension and its passive reduction were diagnostic in 20 of the 24 knees, and the active reduction of posterior subluxation was diagnostic in 18. The reversed pivot shift sign helped to diagnose severe posterior and posterolateral subluxations, but the external rotation recurvatum test was negative in all 24 knees. Stress radiography in near extension revealed a highly significant increase in posterior tibial subluxation in the injured knees.     

Long Term Results of Surgery for Non-Acute Anteromedial Rotatory Instability of the Knee

Seventy-eight patients treated by extraarticular reconstruction including pes anserinus transfer for anteromedial rotatory instability of the knee were reinvestigated 16-47 months (mean 28) after operation. Function before and after operation was assessed by means of a knee rating score. Of these patients, 94 per cent showed a higher score after operation. Twenty per cent showed full recovery with no limitation of knee function whatsoever. The follow-up score was higher with preserved medial meniscus function than when this structure had been removed. When not initially torn, the medial meniscus tended to become involved with time. Mild laxity in extension, possibly indicative of a posterior cruciate injury previously underestimated or not observed, was found in 15 per cent of the patients. No correlation was found between late knee function and the interval between injury and operation or the interval between operation and follow-up examination.

The long term results were good. Extraarticular reconstruction is thus indicated in cases of chronic rotatory instability of the anteromedial type. Routine meniscectomy is not recommended in these patients, however. Signs possibly indicating posterior cruciate ligament involvement should be carefully looked for, as even minor posterior cruciate injury, easily overlooked, may influence the late results.     

Long term results of surgery for non-acute anteromedial rotatory instability of the knee.

Seventy-eight patients treated by extraarticular reconstruction including pes anserinus transfer for anteromedial rotatory instability of the knee were reinvestigated 16--47 months (mean 28) after operation. Function before and after operation was assessed by means of a knee rating score. Of these patients, 94 per cent showed a higher score after operation. Twenty per cent showed full recovery with no limitation of knee function whatsoever. The follow-up score was higher with preserved medial meniscus function than when this structure had been removed. When not initially torn, the medial meniscus tended to become involved with time. Mild laxity in extension, possibly indicative of a posterior cruciate injury previously underestimated or not observed, was found in 15 per cent of the patients. No correlation was found between late knee function and the interval between injury and operation or the interval between operation and follow-up examination. The long term results were good. Extraarticular reconstruction is thus indicated in cases of chronic rotatory instability of the anteromedial type. Routine meniscectomy is not recommended in these patients, however. Signs possibly indicating posterior cruciate ligament involvement should be carefully looked for, as even minor posterior cruciate injury, easily overlooked, may influence the late results.     

Evaluation of the posterior cruciate ligament in long standing cruciate retaining total knee arthroplasty

We evaluated the status of the posterior cruciate ligament in 52 knees with a cruciate retaining total knee arthroplasty 11 years after the index surgery. The evaluation consisted of the Knee Society scores, clinical examination of antero-posterior laxity using the Lachmann test and posterior drawer test. We also used the KT 1000 device, stress radiographs and MRI scan to corroborate this. Three knees were found to be lax clinically and had a posterior tibial shift on radiographs. The MRI scans were able to delineate the posterior cruciate ligament in 86% of the knees. Eleven years after surgery, clinical, radiological and MRI scans when assessed in combination demonstrated the presence of a stable posterior cruciate ligament in 94%.     

Chronic instability after posterior cruciate ligament injury. Tactics, techniques, and results

Summary This article reviews the surgical treatment of chronic posterior knee instability. The treatment rationale includes exact definition of the instability pattern (“envelope-of-motion” of the tibia) by clinical examination, arthrometry and stress radiography. Exact evaluation of the osseous anatomy is mandatory to identify an eventual varus morphotype. This osseous variant in combination with posterior/posterolateral instability should be treated by an osteotomy in every case. The technique of additive osteotomy to correct varus and increase the sagittal tilt of the proximal tibia is described. Ligament reconstruction in chronic posterior knee instability must address the posterior cruciate ligament and the lateral/posterolateral structures in many cases. Patellar tendon grafts, quadriceps tendon grafts or hamstrings can be used for posterior cruciate ligament replacement. Arthroscopic or mini-open techniques may be used for graft placement, direct posterior fixation of the graft via a posterior incision is an option for patellar tendon grafts. Bousquet's biceps plasty or Clancy's biceps tenodesis may be used for posterolateral stabilization; a biceps tendon strip can also be used for lateral collateral ligament reconstruction. Results of surgery are still moderate. In the author's series of chronic posterior/posterolateral instability, 26 cases were treated with posterior cruciate ligament reconstruction and biceps tenodesis. Follow-up at 18 months demonstrated increased stability (mean residual posterior drawer 8 mm at 70 ° and 20 lb force) and improved knee function (33 % IKDC B, 67 % IKDC C). Presently, surgical treatment of chronic posterior knee instability should be restricted to centers devoted to this problem.      

Chronic instability after posterior cruciate ligament injury. Tactics, techniques, and results Taktik, Technik und Ergebnisse

This article reviews the surgical treatment of chronic posterior knee instability. The treatment rationale includes exact definition of the instability pattern (“envelope-of-motion” of the tibia) by clinical examination, arthrometry and stress radiography. Exact evaluation of the osseous anatomy is mandatory to identify an eventual varus morphotype. This osseous variant in combination with posterior/posterolateral instability should be treated by an osteotomy in every case. The technique of additive osteotomy to correct varus and increase the sagittal tilt of the proximal tibia is described. Ligament reconstruction in chronic posterior knee instability must address the posterior cruciate ligament and the lateral/posterolateral structures in many cases. Patellar tendon grafts, quadriceps tendon grafts or hamstrings can be used for posterior cruciate ligament replacement. Arthroscopic or mini-open techniques may be used for graft placement, direct posterior fixation of the graft via a posterior incision is an option for patellar tendon grafts. Bousquet's biceps plasty or Clancy's biceps tenodesis may be used for posterolateral stabilization; a biceps tendon strip can also be used for lateral collateral ligament reconstruction. Results of surgery are still moderate. In the author's series of chronic posterior/posterolateral instability, 26 cases were treated with posterior cruciate ligament reconstruction and biceps tenodesis. Follow-up at 18 months demonstrated increased stability (mean residual posterior drawer 8 mm at 70 ° and 20 lb force) and improved knee function (33 % IKDC B, 67 % IKDC C). Presently, surgical treatment of chronic posterior knee instability should be restricted to centers devoted to this problem.