Anatomical relationship between insertion sites,tunnel placement,and lateral meniscus anterior horn injury during single and double bundle anterior cruciate ligament reconstructions: A comparative macroscopic and histopathological evaluation in cadavers

PurposeThe influence of tunnel extension outside the anatomical anterior cruciate ligament (ACL) insertion in single-bundle (SB) or double-bundle (DB) ACL reconstruction is unclear. This study aimed to investigate the anatomical relationship between ACL insertion and tunnel extension in SB and DB ACL reconstruction, and the impact of tibial tunnel extension to the insertion of anterior horn of lateral meniscus in terms of injury.MethodsForty-six paired cadaver knees (mean age, 82.7 ± 10.7 years) were used. Right and left knees were used for SB (10 mm) and DB tunnel reaming (6 mm for the anteromedial and posterolateral bundles). Tibial and femoral tunnels were created to aim at the center of the ACL insertion by arthroscopic visualization. The relationship between tunnel extension and ACL insertion was evaluated macroscopically, and there ratio in two groups were compared by chi-square test. Further, the relative risk for meniscus injury based on tunnel placement was estimated. Coronal section of tibia and parallel section to Blumensaat line in femur were prepared to evaluate the relationship among tunnel position, ACL insertion, and anterior horn of the meniscus histologically.ResultsTibial tunnel extension out of the ACL insertion was observed macroscopically in 9 (39.1%) knees of the SB group, and 3 (13.0%) of the DB group (p = 0.045). In femoral tunnels, extension out of the ACL insertion was seen in 8 (34.8%) knees of the SB group and 1 (4.3%) of the DB group (p = 0.011). Partial injuries of the lateral meniscus anterior horn (LMAH) were observed in 5 (21.7%) knees of the SB group and 1 (4.3%) knee of the DB group (p = 0.091). The relative risk for LMAH injury was calculated as 5.0 (odds ratio, 6.1). Microscopically, SB tunnels appeared to expand out of ACL insertion, both in the femur and tibia.ConclusionsThe incidence of tunnel extension out of the ACL insertion in femur and tibia were higher with SB than with DB reconstruction. Furthermore, injury rate of the LMAH in the DB group was lower.     

Arthroscopic studies of variants of the anterior horn of the medial meniscus

The objective of this study was to arthroscopically analyse the morphology and dynamics of variants of the anterior horn of the medial meniscus of the knee (VAMM) and to then consider the pathological significance of these variants. VAMM was defined as knees in which the anterior horn of the medial meniscus is not attached to the tibia. Between April 1992 and March 1995, arthroscopy was performed on 953 knees of 903 patients. At the time of this examination, observation and probing were performed to determine the condition of the synovium, the synovial plica, the cartilage in all compartments, the meniscus, the cruciate ligaments, and the popliteal tendon. In particular, detailed examination was made of the anterior horn of the medial meniscus with regard to the point of insertion to the tibia and the degree of movement in knee flexion/ extension. Cases of VAMM diagnosed on the basis of the arthroscopic findings were classified into the following four categories: the ACL (anterior cruciate ligament) type, where the anterior horn of the medial meniscus was attached to the ACL; the transverse ligament type, where the anterior horn of the medial meniscus was attached to the transverse ligament; the coronary ligament type, where the anterior horn of the medial meniscus was attached to the coronary ligament; and the infrapatellar fold type, where the anterior horn of the medial meniscus was attached to the infrapatellar synovial fold. These patients were then analyzed with regard to the arthroscopic findings and the intra-articular lesions other than VAMM. In 98 (10.9%) of the total patients, 103 knees were classified as VAMM. Classification of those 103 knees using the above criteria showed 39 ACL type knees, 51 transverse ligament type knees, 11 coronary ligament type knees, and 2 infrapatellar fold type knees. The arthroscopic findings indicated that the anterior horn of the medial meniscus was not attached directly to the tibia in any of these knees. Probing and flexion/extension of the knee revealed hypermobility at the anterior horn of the medial meniscus. In this study, anterior knee pain syndrome was diagnosed in 12 (11.7%) of the 103 VAMM knees. In addition, there was no clear history of trauma in 20 of 23 knees found to have an isolated medial meniscus tear. In these cases, even detailed arthroscopic observation proved the causes of the symptoms or injury. On the basis of these findings, we surmised that the anterior portion shows hypermobility at the time of flexion/extension of the knee, regardless of the type of VAMM. In this study, we discussed the possibility that the existence of VAMM may become the cause of pain or injury to the meniscus.     

Spontaneous healing of acute anterior cruciate ligament (ACL) injuries - conservative treatment using an extension block soft brace without anterior stabilization

To evaluate the spontaneous healing capability of acute anterior cruciate ligament (ACL) injuries, conservative treatment was applied in a selected group of 31 patients, who had low athletic demands. Each patient demonstrated a continuous ACL on magnetic resonance imaging (MRI), from the original femoral attachment through the tibial attachment, and an area of high intensity was detected in the substance of the ACL. The injured knees were treated using an extension block soft brace without anterior stabilization for 2-3 months. KT-2000 and MRI examinations were carried out regularly during the follow-up. Twenty-three knees (74%) were revealed to be stable in the follow-up examination, with an average of 16.1 months elapsing since the initial injuries. The KT-2000 side-to-side differences of 20 knees were less than 3 mm, and those of the other 3 knees were more than 3 mm but less than 5 mm. MRI confirmed that 21 injured ACL out of 23 knees maintained a femoral to tibial attachment and showed gradual reductions in image intensity. The positions of the other 2 injured ACL femoral attachments were different from the original femoral attachment: one was attached to the posterior cruciate ligament, and the other was located at the lateral femoral condyle anterior to the original femoral attachment. Eight knees (26%) subsequently required ACL reconstructions due to instability. This study indicates that an acutely injured ACL has healing capability. It also suggests that conservative management of the acute ACL injury can yield satisfactory results in a group of individuals who have low athletic demands and continuous ACL on MRI, provided the patients are willing to accept the slight risk of late ACL reconstruction and meniscal injury.     

膝关节前交叉韧带胫骨止点的软组织解剖标记

背景：膝关节前交叉韧带（ACL）重建时,胫骨骨道定位不准会产生重建韧带与髁间窝的撞击或起不到维持膝关节稳定性的作用。因此,确定ACL胫骨止点的位置非常重要。目的：研究膝关节ACL胫骨止点前内束（AMB）和后外束（PLB）与软组织标记后交叉韧带（PCL）和外侧半月板前角的距离,从而明确ACL胫骨止点在胫骨平台的位置,为ACL损伤双束重建提供理论支持。方法：解剖18个膝关节尸体标本（左膝10个,右膝8个）,测量ACL中点、AMB中点、PLB中点与PCL和外侧半月板前角的距离,并分析左、右膝关节是否存在差异。结果：AMB中点与PCL和外侧半月板前角的距离分别为（15.00±3.97）mm和（19.78±4.10）mm;PLB中点与两者的距离分别为（10.17±5.56）mm和（19.50±4.40）mm;ACL中点与两者的距离分别为（12.67±4.52）mm和（19.61±3.87）mm。左右膝关节ACL中点、AMB中点、PLB中点与软组织解剖标记的距离无明显统计学差异。结论：膝关节ACL损伤行手术重建时,可采用PCL和外侧半月板前角作为定位标记。     

内侧半月板后角Ramp损伤在前十字韧带损伤患者中的发生率及影响因素分析

 目的 研究前十字韧带损伤合并内侧半月板后角 Ramp(内侧半月板后角至后内侧关节 囊滑膜移行区域)损伤的发生率, 并分析其影响因素。方法 2002年 4月至 2007年 10月, 采用韧带重 建手术治疗并确诊为前十字韧带损伤的患者 868例, 男 609例, 女 259例;年龄 15~55岁, 平均 25.2岁。根据手术记录以及术中关节镜探查, 筛选其中存在内侧半月板后角 Ramp损伤的病例, 计算其发生率。 按照性别、年龄段及受伤至手术时间分组, 分析 Ramp损伤发生率的影响因素。结果 868例膝关节确诊为前十字韧带损伤并接受韧带重建手术的患者中, 内侧半月板后角 Ramp损伤的患者为 144例, 男 113例, 女 31例;平均年龄 24.7岁。受伤至手术时间平均 29.3个月。 Ramp损伤的发生率为 16.59% (144/868), 伤后 6周、3、6、12、24个月 Ramp损伤的发生率分别为 12.66%、13.51%、13.17%、14.49%、 15.92%;男性发生率为 18.56%(113/609), 女性为 11.97%(31/259), 两者比较差异有统计学意义;30岁以下的患者 Ramp损伤发生率为 21.59%(114/528), 30岁以上者为 8.82%(30/340), 两者比较差异有统 计学意义。结论 内侧半月板后角 Ramp损伤是前十字韧带断裂的常见合并损伤, 其发生率为 16.59%; 伤后 2年内, Ramp损伤的发生率随受伤时间延长明显增加;男性及 30岁以下患者 Ramp损伤发生率明 显增高。     

Chronic anterior cruciate ligament deficiency is associated with increased anterior translation of the tibia during the transition from non-weightbearing to weightbearing.

Translation of the tibia relative to the femur was measured while a group of subjects with normal knees and group with anterior cruciate ligament (ACL) tears underwent transition from non-weightbearing to weightbearing stance. Subjects were positioned in the Vermont knee laxity device (VKLD) with muscles relaxed and the limb segment and compressive joint load offset (non-weightbearing). A lateral radiograph of the knee, with the posterior aspects of the femoral condyles superimposed, was obtained to document the position of the tibia relative to the femur. Immediately after, a compressive load equal to 40% of bodyweight was applied to each foot, and a second radiograph was obtained to document the change in position of the tibia relative to the femur. The transition from non-weightbearing to weightbearing produced a significant increase of anterior translation of the tibia relative to the femur (mean; 3.4 mm) for the subjects with ACL tears compared with the contralateral normal knees (0.8 mm). Similarly, there was a significant increase in anterior translation of the tibia for the subjects with ACL tears compared to the group of subjects with normal knees (1.2 mm). The fourfold increase in anterior translation of the tibia for the knees with ACL tears compared to the contralateral side is a concern because it is substantially greater than the 95% confidence limits of the side-to-side differences in anterior-posterior knee laxity measured from subjects with normal knees. This observation could explain, at least in part, one of the mechanisms that initiates damage to the meniscus and articular cartilage in subjects that have suffered an ACL tear.     

Objective anterior cruciate ligament testing

We examined subjects with the Stryker knee laxity tester as part of the clinical examination to determine its usefulness in evaluating the anterior cruciate ligament. We measured 123 athletes with no history of knee injury, as well as 30 patients with ACL injury proven by arthroscopy, and 11 injured patients with intact ACL at arthroscopy. We recorded anterior and posterior tibial displacement at 20 degrees of knee flexion and 20 lbs force in each direction. Anterior laxity and side to side difference correlated with ACL injury; posterior and total AP laxity did not. In normal subjects, mean anterior laxity was 2.5 mm. Only 8% of normal knees had anterior laxity of 5 mm or more. Ten percent of normal subjects had a side to side difference of 2 mm or more. In ACL tears, mean laxity was 8.1 mm, with 94% measuring 5 mm or more. Of the subjects, 89% with unilateral ACL injury had an increase of 2 mm or more on the injured side. Ten of ten acute ACL tears were detected by these criteria, with no false positives. In injured knees with intact ACL, measurements did not differ significantly from normal. We found the objective knee laxity measurement to be a useful complement to clinical knee examination.     

Dislocating anterior horn of the medial meniscus

Dislocating anterior horn of the medial meniscus was found in 15 knees of 13 patients during arthroscopic examinations done between 1992 and 1995. All of them were available for follow-up evaluation (4 by telephone). There were 11 men and 2 women (average age, 28 years; range, 17 to 49 years). Nine knees had a history of trauma. Only 1 knee had had trauma in two bilateral cases. Duration of symptoms was an average of 3.3 years (range, 3 months to 10 years). The knees were stable clinically. Arthroscopy revealed associated lesions in 13 knees; hypertrophic medial plicae, meniscal, chondral and anterior cruciate ligament (ACL) lesions predominated. Three knees had unusually hypertrophic ligamentum mucosum. Eleven of 13 knees had more than one associated lesions. Only 2 knees (2 patients) had isolated dislocating anterior horn of the medial meniscus. Only the associated lesions were treated (except for ACL lesions) and dislocating anterior horns of the medial menisci were left alone. Follow-up averaged 21 months (7 to 40 months). At follow-up, 11 knees were graded as excellent, 3 as good, and 1 as fair according to the Lysholm scale. Eight knees had minor symptoms and 6 were asymptomatic; no improvement was noted in 1 knee. Overall, 12 patients (14 knees) were satisfied with their treatment. Dislocating anterior horn of the medial meniscus is a normal anatomic variant with little or no clinical significance. When seen during arthroscopy, a significant lesion should be looked for. It is an incidental finding and should be left alone.Arthroscopy 1998 Apr;14(3):246-9     

前十字韧带断裂继发半月板损害的临床研究

目的研究前十字韧带(anteriorcruciateligament,ACL)断裂对半月板的影响。方法回顾分析1984年12月～1999年12月间收治的419例ACL断裂患者半月板的损伤情况及其与软骨损伤的关系。结果外侧半月板的损伤率随病程增加无显著变化,而内侧半月板的损伤率随病程增加显著增加,由急性期的31.1%增至亚慢性期的48.2%(P<0.01),又增至慢性期的78.8%(P<0.001)。内侧半月板后角损伤率较前角高,差异有显著性意义(P<0.05)。损伤形态以纵裂最常见,随着病程的增加,半月板损伤也越发复杂。内侧半月板损伤患者的内髁软骨损伤的发生率要高于内侧半月板正常者的内髁软骨损伤发生率,但差异无显著性意义(P>0.05);而外侧半月板损伤患者的外髁软骨损伤的发生率却显著高于外侧半月板正常者,差异有非常显著性意义(P<0.01)。结论ACL断裂可伴发和继发半月板的损害,ACL断裂时伴发的多为外侧半月板的损伤,而继发的半月板损害却以内侧为重。内髁软骨损害主要由股胫关节前后向不稳、异常活动增加造成,而与内侧半月板的损伤关系不大。     

The relation between static and dynamic knee stability after ACL reconstruction

The purpose of this prospective study was to quantify and compare the amount of anterior tibial translation (ATT) occurring in ACL-reconstructed knees during both a static passive Lachman test and an isokinetic knee extension exercise, pre- and postoperatively. Stress-radiography combined with an electrogoniometer system was applied to 49 knees before and after ACL reconstruction. The Lysholm score was calculated and subjective evaluation assessed before operation and at follow-up. Both measurement methods confirmed a significant decrease of ATT after surgery. Side-to-side differences in ATT were seen in the passive Lachman test postoperatively, and were not found during isokinetic extension from 90 degrees to 0 degree. There was no significant correlation between static passive stability and the functional knee score at follow-up. In addition, the patients with a more than 3 mm side-to-side difference in the passive Lachman test after surgery, showed less than a 1 mm side-to-side difference during isokinetic exercise at a flexion angle of 20 degrees. These results suggest that ACL reconstruction improves ATT in both tests, but the side-to-side difference is greater with the static Lachman test.     

The early treatment of motion complications after reconstruction of the anterior cruciate ligament.

The use of active and passive knee motion in the immediate postoperative period and a treatment plan for early postoperative limitations in knee motion has proven highly effective in restoring motion after anterior cruciate ligament (ACL) reconstruction. Of 207 knees, 189 (91%) regained a full range of motion of 0 degrees-135 degrees. The remaining 18 knees (9%) did not regain motion as rapidly as the others and were placed in an early postoperative phased treatment program. Six knees had serial extension casts, nine had early gentle manipulation under anesthesia, and three had arthroscopic lysis of intraarticular adhesions and scar tissue. Fourteen of these 18 knees regained a full range of knee motion. Two of the remaining four knees lacked 5 degrees of full extension, whereas the other two, in patients who had failed to follow medical advice and the rehabilitation program, had permanent and significant limitation of motion. The incidence of postoperative motion problems was related to the extent of the surgical procedure. The incidence was 4% in patients who had only ACL reconstruction, 10% in cases in which added lateral extraarticular procedure had been done, 12% where a meniscus repair had been done, and 23% where a medial collateral ligament repair was done.     

Quantitative evaluation of anterior tibial translation during isokinetic motion in knees with anterior cruciate ligament reconstruction using either patellar or hamstring tendon grafts

We studied 79 patients with unilateral injury to the anterior cruciate ligament (ACL). The patients were randomly allocated to reconstruction with autologous patellar bone-tendon-bone (BTB) grafts (49 knees) or hamstring tendon (ST) grafts (30 knees). We measured anterior tibial translation (ATT) during isokinetic concentric contraction exercise 18-20 months after surgery using a computerized electrogoniometer. In both groups the highest ATT during exercise was observed at a knee flexion of about 20 degrees and was 13.5+/-3.0 mm in the BTB group and 13.9+/-3.4 mm in the ST group. There was no difference in the ATT between the reconstructed and healthy knees. For a range of knee flexion between 30 and 50 degrees the ATT in the ST group was significantly higher on the reconstructed side than on the healthy side. In the BTB group, the mean ATT in the reconstructed group was similar to that on the healthy side at a knee flexion angle between 0 and 90 degrees .     

Arthroscopy in acute injuries of anterior cruciate-deficient knees: fresh and old intraarticular lesions

Sixty-four patients out of a much larger population who presented within 2 weeks of an acute injury to the knee were found at arthroscopy to have either a chronic tear or chronic incompetent anterior cruciate ligament (group I, 32 patients) or to have an acutely torn anterior cruciate ligament (ACL) (group II, 32 patients). Arthroscopy of both groups allowed the author to compare and contrast the lesions found in each group. Chondromalacia of the femorotibial joint is significantly more frequent in chronic ACL-deficient knees (p less than 0.05), and there is a tendency to degenerative meniscus lesions and chondromalacia patella in these knees too.     

Proprioception of the knee before and after anterior cruciate ligament reconstruction

Purpose: The purpose of this study was to determine, first, if there is measurable deficit in proprioception in an anterior cruciate ligament (ACL)-deficient knee, either compared to the contralateral knee or external controls; second, if this deficit, if present, improves after ACL reconstruction; and third, if improvement occurs, what the time course of improvement is. Type of Study: Prospective cohort study. Methods: Patients undergoing ACL reconstruction at the University of Chicago, demonstrating a full and painless range of motion and no other knee ligament injury or history of previous knee surgery, were eligible. Twenty-six patients, with an average age of 25 years (range, 16 to 48) were enrolled. Average time from injury to reconstruction was 8 weeks. The patients' contralateral knee served as an internal control, and 26 age-matched and gender-matched healthy volunteers were enrolled as an external control group. ACL reconstructions were performed using a single-incision technique with either bone–patellar tendon–bone or quadrupled hamstring autograft. They were allowed immediate weightbearing as tolerated and participated in a standardized rehabilitation program, with the goal of returning to sport at approximately 6 months. Proprioception testing was carried out using an electrogoniometer, in a seated position. Joint position sense (JPS) and threshold to detection of passive motion (TDPM) were measured preoperatively and at 3 and 6 weeks and 3 and 6 months postoperatively. Results: Mean KT-2000 values 6 months postoperatively were 1.38 mm (±2). Modified Lysholm score improved significantly (P < .01). Calculated r values were 0.65 for JPS and 0.96 for TDPM. No significant differences in postoperative proprioception were found between hamstring and patellar tendon grafts or among patients with meniscus injury, meniscus repair, or chondral injury. Preoperatively, the mean TDPM in both the injured and contralateral knees was significantly higher (worse) than in the external control knees (P = .008; P = .016). Evaluation of changes in proprioception from preoperative to 6 months postoperative showed significant improvement in both injured and contralateral knees (P = .04; P = .01). At 6-month follow-up, there was no significant difference from controls. Conclusions: TDPM was a more reliable method than JPS for testing proprioception before and after ACL reconstruction in this study. Bilateral deficits in knee joint proprioception (TDPM) were documented after unilateral ACL injury. Reconstruction of a mechanical restraint (ACL graft) was believed to have a significantly positive impact on early and progressive improvement in proprioception.     

Primary repair plus intra-articular iliotibial band augmentation in the treatment of an acute anterior cruciate ligament rupture

Between September 1987 and November 1989, we treated 90 consecutive patients with an acute anterior cruciate ligament (ACL) rupture with the multiple suture technique and iliotibial band augmentation. Seventy of these patients were re-examined 2 to 5 years after the operation (mean 3.5 years), the examination consisting of a questionnaire, clinical examination, laxity tests with the KSS machine (Acufex), radiological examination and isokinetic muscle strength testing (Cybex 6000). There were 32 men and 38 women (mean age 34 years). The injury was sustained in sports in 44 (63%) cases, and the sports most frequently involved were downhill skiing (18 cases), soccer (9 cases) and volleyball (5 cases). Of the injuries, 38 were isolated ACL ruptures and 31, ACL ruptures combined with a medial CL rupture. In 9 cases, an additional meniscus injury and in one case an additional posterior CL - lateral CL rupture was found. At the follow-up, 55 patients (79%) were satisfied with the end result, and according to our objective functional criteria 55 (79%) had an excellent or good outcome. According to the Lysholm score, 53 (76%) patients were excellent or good ( 82 points). In the Lachman test, 29 knees (41%) were completely stable. The Lachman test was mildy positive in 40 knees (57%) (36 had 1+ laxity and 4, 2+ laxity), and one patient had 3+ laxity with a hard end-point. Similarly, the anterior drawer test was negative in 53 knees (76%); and the other 17 (24%) had mild laxity (16 had 1+ laxity and 1, 2+ laxity). The total anterior-posterior laxity measured with the KSS averaged 9.7 ± 3.5 mm in the injured knee and 7.3 + 3.0 mm in the uninjured knee (the laxity measured at a knee angle of 20° of flexion). Corresponding values at a knee angle of 90° of flexion were 6.1 ± 2.4 mm and 4.7 ± 1.9 mm, respectively. The pivot shift test was negative in 62 patients (89%) and l+ positive in the remaining 8 patients (11%). Fifty-eight patients (83%) had full knee extension and 40 patients (57%), full knee flexion. Compared with the uninjured knee, the operated knees showed an average 14% strength deficit in isokinetic knee extension and 6% deficit in flexion at the speed of 60°/s. At the speed of 180°/s, the corresponding deficits were 8% and 4%, respectively. Of the 44 patients who were active in sport before the injury, 40 (91%) were able to return to sports. A flexion deficit of 5° or more was associated with thigh muscle atrophy (P < 0.05) and quadriceps weakness, both at the slow speed (P < 0.05) and high speed (P < 0.001) of the isokinetic movement. In conclusion, in an acute rupture of the ACL, primary repair of the ligament with intraarticular iliotibial band augmentation seems to be a good method to restore the functional capacity of the injured knee.     

Arthroscopic management of mucoid degeneration of anterior cruciate ligament

Background:

Mucoid degeneration of the anterior cruciate ligament (ACL) is a less understood entity. The purpose of this study was to diagnose mucoid degeneration of anterior cruciate ligament and to assess the effectiveness of arthroscopic treatment in these patients.

Materials and Methods:

Between December 2007 and November 2011, 20 patients were diagnosed to be suffering from mucoid degeneration of anterior cruciate ligament (ACL) on the basis of magnetic resonance imaging (MRI), histopathology, and arthroscopy findings. 12 patients were males and 8 patients were females, with mean age of 42.2 years for males (range 28-52 years) and 39.4 years for females (range 30–54 years). They presented with pain on terminal extension (n=10) and on terminal flexion (n=2) without history of significant preceding trauma. MRI showed an increased signal in the substance of the ACL both in the T1- and T2-weighted images, with a mass-like configuration that was reported as a partial or complete tear of the ACL by the radiologist. At arthroscopy, the ACL was homogenous, bulbous, hypertrophied, and taut, occupying the entire intercondylar notch. A debulking of the ACL was performed by a judicious excision of the degenerated mucoid tissue, taking care to leave behind as much of the intact ACL as possible. Releasing it and performing a notchplasty treated impingement of the ACL to the roof and lateral wall. In one patient, we had to replace ACL due to insufficient tissue left behind to support the knee.

Results:

Good to excellent pain relief on terminal flexion–extension was obtained in 19 of 20 knees. The extension deficit was normalized in all knees. Lachman and anterior drawer test showed a firm endpoint in all, and 85% (n=17) showed good to excellent subjective satisfaction.

Conclusions:

Mucoid hypertrophy of the ACL should be suspected in elderly persons presenting pain on terminal extension or flexion without preceding trauma, especially when there is no associated meniscal lesion or ligamentous insufficiency. They respond well to a judicious arthroscopic release of the ACL with notchplasty.     

Mechanisms of anterior cruciate ligament injury

This study examined the mechanisms of anterior cruciate ligament (ACL) injury. In the first part of the study, using a comprehensive, standardized questionnaire, 89 athletes (100 knees) were interviewed about the events surrounding their ACL injury. A noncontact mechanism was reported in 71 (72%) knees and a contact injury in 28 (28%) knees; one patient was unsure if there was any contact. Most of the injuries were sustained at footstrike with the knee close to full extension. Noncontact mechanisms were classified as sudden deceleration prior to a change of direction or landing motion, while contact injuries occurred as a result of valgus collapse of the knee. Hamstring flexibility parameters revealed a statistically higher level of laxity in the injured athletes compared with a matched group of 28 controls. In the second part of the study, videotapes of 27 separate ACL disruptions were reviewed and confirmed that most noncontact injuries occur with the knee close to extension during a sharp deceleration or landing maneuver. Because the knee is in a position to allow the extensor mechanism to strain the ACL and maximum, eccentric muscle force conditions usually apply, the quadriceps may play an important role in ACL disruption. Passive protection of the ACL by the hamstring muscles may be reduced in patients with above-average flexibility.     

Simultaneous reconstruction of anterior cruciate ligament and posterior cruciate ligament by using allogeneic patellar tendon under arthroscopy

With fast development of arthroscopic surgery inChina, simple reconstruction of ACL (anteriorcrucial ligament) or PCL has been reported in number. However , the methods concerningsimultaneous reconstruction of ACL and PCL are rarelyreported. Simultaneous …     

Intra-articular mechanical blocks and full extension in patients undergoing anterior cruciate ligament reconstruction.

Patients with acute anterior cruciate ligament (ACL) rupture frequently present with a lack of full extension. Current literature is unclear whether arthroscopic debridement is necessary before reconstruction to achieve full extension postoperatively. This study examined the postoperative extension achieved in 153 knees that underwent ACL reconstruction within 12 weeks of index injury. All patients performed preoperative physical therapy to increase range of motion and control pain/swelling, regardless of presenting range of motion without prior aspiration or arthroscopy. Of the 153 knees, 103 had meniscal pathology, of which 73 were peripheral vertical tears; 96 of the 153 knees lacked >/=3 degrees extension preoperatively. Five of 96 knees had an intra-articular mechanical block to extension and all regained full extension after ACL reconstruction. This study documented that a true intra-articular mechanical block is unusual in primary ACL ruptures. Lack of full extension can be adequately dealt with during surgical reconstruction without a detrimental effect on knee extension postoperatively.     

Displaced bucket handle tears of the medial meniscus masking anterior cruciate deficiency

Traditionally, anterior cruciate ligament (ACL) injuries have been difficult to diagnose in the Casualty Department. Studies have shown that the anterior drawer test has a poor sensitivity both in acute and chronic ACL deficient knees [4, 6, 9]; thus, more emphasis has been placed on the pivot shift and Lachman tests [3]. We report four cases of proven ACL rupture where clinical examination revealed an absent pivot shift and a near normal Lachman test following a displaced bucket handle tear of the medial meniscus. This finding has been reproduced in cadaver studies, and we conclude that if the history strongly suggests an ACL injury and examination reveals a stable knee, then the dual pathology of medial meniscus tear and ACL rupture should be suspected.