The effect of anterior cruciate ligament reconstruction on symptoms of pain and instability in patients who have previously undergone meniscectomy: A prereconstruction and postreconstruction comparison

To determine the effect of anterior cruciate ligament (ACL) reconstruction on symptoms of pain and instability in patients with chronic ACL insufficiency who had previously undergone meniscectomy, we reviewed a series of 21 symptomatic, previously meniscectomized patients with chronic ACL deficiency (average age, 31 years). Arthroscopically assisted intra-articular ACL reconstruction using a middle, one-third patella-tendon autograft was performed in all cases. All patients had radiographic evidence of degenerative changes before ACL reconstruction. The average time from meniscectomy to ACL reconstruction was 6.6 years. Preoperative and postoperative range of motion, stability, and subjective evaluations were compared. Follow-up averaged 37.4 months (range, 24 to 67 months). Physical examination and postoperative KT-1000 side-to-side measurements revealed three patients (14%) with pathological ligament laxity. One patient had a 2+ Lachman, a 2− pivot shift, and >5 mm difference on KT-1000 maximum manual test, and two patients had a 1+ Lachman and a 1+ pivot shift. Range of motion measurements taken at follow-up were not significantly different from preoperative measurements (extension, P = .14; flexion, P = .46). Subjectively, all items on a panel of 15 visual analog scales were improved, but intensity of pain and instability were significantly improved after statistical analysis (P < .05). This review suggests that symptoms of pain and instability in patients with chronic ACL deficiency who have previously undergone meniscectomy can be improved by ACL reconstruction if objective stability is obtained.     

Anatomic variations between Japanese and Caucasian populations in the healthy young adult knee joint

Our objective was to characterize variations in mechanical knee alignment, tibial torsion, tibial width, and ACL laxity measurements between Japanese and Caucasian populations in the healthy, young adult knee joint. Seventy young adult subjects participated in this study, including 23 Japanese and 47 Caucasian subjects. Coronal magnetic resonance images of the hip, knee, and ankle were acquired for analysis. Japanese subjects had a significantly higher (p = 0.04) varus alignment (1.64 ± 0.43° standard error) than Caucasians (0.55 ± 0.33°), while women exhibited a more valgus alignment (0.16 ± 0.52°) than men (0.94 ± 0.42°, p = 0.04). Significant differences were found in tibial torsion and ACL laxity (p < 0.01) between ethnicities, with Japanese exhibiting lower tibial torsion (33.4 ± 10.0°) and higher ACL laxity (7.5 ± 0.4 mm) measurements compared to Caucasians (38.9 ± 9.5° and 5.7 ± 0.3 mm, respectively). Significant differences between genders were found in hip‐knee‐ankle alignment (p = 0.04), tibial width (p < 0.0001), and ACL laxity (p < 0.01) measurements. Measurements were reliable between observers and for repeated positioning. Our study provides new insight into anatomical and geometric differences in the knee joint between Japanese and Caucasians, as well as between females and males. Further consideration of these results may improve development of implants to accommodate for these differences, and understanding of characteristics leading to increased prevalence of knee OA in certain populations. The use of magnetic resonance imaging to obtain these measurements also allows soft tissue structure characterization without exposure to ionizing radiation. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res     

Can suture repair of ACL transection restore normal anteroposterior laxity of the knee? An ex vivo study

Recent work has suggested the transected anterior cruciate ligament (ACL) can heal and support reasonable loads if repaired with sutures and a bioactive scaffold; however, use of a traditional suture configuration results in knees with increased anterior–posterior (AP) laxity. The objective was to determine whether one of five different suture repair constructs when performed at two different joint positions would restore normal AP knee laxity. AP laxity of the porcine knee at 60° of flexion was evaluated for five suture repair techniques. Femoral fixation for all repair techniques utilized a suture anchor. Primary repair was to either the tibial stump, one of three bony locations in the ACL footprint, or a hybrid bony fixation. All five repairs were tied with the knee in first 30° and then 60° of flexion for a total of 10 repair constructs. Suture repair to bony fixation points within the anterior half of the normal ACL footprint resulted in knee laxity values within 0.5 mm of the ACL‐intact joint when the sutures were tied with the knee at 60° flexion. Suture repair to the tibial stump, or with the knee at 30° of flexion, did not restore normal AP laxity of the knee. Three specific suture repair techniques for the transected porcine ACL restored the normal AP laxity of the knee at the time of surgery. Additional studies defining the changes in laxity with cyclic loading and in vivo healing are indicated. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1500–1505, 2008     

Double-band reconstruction of the ACL using a synthetic implant: a cadaveric study of knee laxity

In this study, the anterior laxity and internal rotation of five cadaveric knee joints were compared when the anterior cruciate ligament (ACL) was intact, after its reconstruction with the anteromedial band (AMB) only, then after its reconstruction with the double band, with the posterolateral band (PLB) tensioned first at 20° and then at 90°, and finally with the ACL resected. The tests were performed using a mechanical apparatus that allowed the joint 6° of freedom and also the application of external loads and torques on the tibia. The loads used were 50, 90, and 130N for the anterior laxity test, and a torque of 2, 3, and 4Nm in the internal rotation test. In all cases, laxity with double-band reconstruction was closer to the natural value than when it was constructed with the AMB only. In some cases, double-band reconstruction imposed a higher constraint on the joint than did the natural ACL. Measurement of the residual tension on the PLB after its final anchoring was also performed during passive flexion. This test revealed a high tension on this band with the knee in hyperextension, followed by a decrease in value through to 45° and a slight increase at 90°, thus following a similar trend to that of the natural PLB.     

Does the peak torque of the hamstring and quadriceps muscles affect the knee laxity measurements in male patients with anterior cruciate ligament rupture?

The aim of the study was to examine whether the peak torque of the hamstring and quadriceps muscles affects the anterior knee laxity measurements in male patients. The study comprised 45 male patients who had a chronic unilateral anterior cruciate ligament (ACL) rupture. Preoperatively, one experienced physiotherapist performed all the KT-1000 examinations. The anterior displacement was registered at 89 Newton. Immediately after the KT-1000 examination, an isokinetic concentric peak torque measurement was performed at 60°/s for both the hamstring and quadriceps muscles. The anterior displacement was significantly larger in the ACL-ruptured knees compared with the noninjured knees (p < 0.001). Patients with strong hamstring muscles on the injured side displayed significantly less knee laxity compared with patients with less strength (p = 0.018). There was an inverse correlation between the peak torque of the hamstring muscles and the KT-1000 anterior laxity measurements in the ACL-ruptured knees (rho = −0.37, p = 0.01). We conclude that male patients with strong hamstring muscles display smaller KT-1000 laxity measurements than patients with less strength. Received: 22 January 2001/Accepted: 24 January 2001     

Arthroscopic anatomic double bundle anterior cruciate ligament reconstruction: Our experience with follow-up of 4 years

BackgroundDouble bundle (DB) anterior cruciate ligament (ACL) reconstruction has been proposed to recreate the natural anatomy of ACL. Reconstruction of the anatomy of both the bundles of ACL has been thought to be able to restore the rotational stability of the knee joint. Nevertheless, it remains unclear whether DB reconstruction has better functional outcome than single bundle (SB) ACL reconstruction.PurposeTo evaluate the clinical outcomes, patient satisfaction and manual laxity tests of knee in patients treated with DB ACL reconstruction in Indian population.MethodsWe prospectively followed 25 patients with an isolated ACL injury operated for DB ACL reconstruction after applying the inclusion and exclusion criteria. Patients were evaluated pre-operatively and in the post-operative period at regular intervals with the minimum follow up of 4 years. Clinical stability was assessed by anterior drawer test, Lachman test and pivot shift test. Functional outcome was assessed by IKDC, Lysholm and Modified Cincinnati scores.ResultsAt the end of 4 years, functional outcome in terms of all subjective scores was satisfactory. Graded stability results of the Lachman, Anterior drawer and pivot shift tests were almost near to that in normal knee. No complication occurred post-operatively.ConclusionAnatomical DB ACL reconstruction seems to offer satisfactory results in terms of subjective scores and stability tests to patients with ACL tear. It has been found to be associated with no obvious complications and no failures. However a larger patient pool is desired for conclusive results.     

Effect of implant lengthening and mode of fixation on knee laxity after ACL reconstruction with an artificial ligament: a cadaveric study

An "apparent" lengthening of the ligament implant, which causes an increase in knee laxity after the reconstruction of the anterior cruciate ligament (ACL) may be due to either slippage of the implant from under the fixation devices, or tunnel migration (due to bone resorption). These two mechanisms are related to the initial ligament placement, implant tensioning, and fixation modes. This cadaveric study simulates, in a controlled experimental situation, the postoperative lengthening of artificial ACL implants, and seeks to quantify the consequent increase in joint laxity. Eight cadaveric right knees, in which the Leeds-Keio artificial ligament was implanted, were tested in a specially constructed apparatus, which allowed the knee joint six degrees of freedom. In each of the tested joints the laxity was measured under several test conditions for two final fixation modes of the implant. The difference between the fixation modes was the application (as in mode B) or not (as in mode A), of a posteriorly directed force of 50 N on the tibia, at the moment of final fixation of the ligament. In both cases a tensile load of 50 N was maintained along the implant. All measurements were taken at flexion angles of 20° and 90° and with controlled implant lengthening of up to 3 mm in 0.5-mm increments. After implantation, adopting fixation mode B resulted in the knee exhibiting an anterior laxity considerably less than the original physiological laxity, compared with that measured after using fixation mode A. Thus at 20° of knee flexion, under an anterior load of 100 N applied on the tibia, adopting fixation mode B, the joint laxity was 2.8 mm smaller than the natural laxity, whereas, for fixation mode A, it was 1.4 mm larger. At 90° of knee flexion, the situation was similar, but with smaller differences. However, the situation was overturned as the implant length was increased. Thus, at 20° of knee flexion, when the implant was lengthened in a range of 1–2 mm, the laxity observed with fixation mode B was similar to that recorded when the ACL was intact, whereas the laxity observed with fixation mode A was about 3–4 mm greater. Similar data were observed at 90° of knee flexion. It appears that fixing the implant finally by applying a tensile load on it while simultaneously pushing the tibia posteriorly could be an effective measure against the possible return of joint laxity. Received: September 12, 2000 / Accepted: January 18, 2001     

The use of platelets to affect functional healing of an anterior cruciate ligament (ACL) autograft in a caprine ACL reconstruction model

Many anterior cruciate ligament (ACL) reconstructions have increased laxity postoperatively. We hypothesized that enhancing an ACL graft with a collagen‐platelet composite (CPC) would improve knee laxity and graft structural properties. We also hypothesized the platelet concentration in the CPC would affect these parameters. Twelve goats underwent ACL reconstruction with autologous patellar tendon graft. In six goats, a collagen‐platelet composite was placed around the graft (CPC group). In the remaining six goats, the collagen scaffold only was used (COLL group). Three goats were excluded due to complications. After 6 weeks in vivo, anterior–posterior (AP) laxity and tensile properties of the ACL reconstructed knees were measured and normalized against the contralateral intact knee. At a knee flexion angle of 30°, the average increase in AP laxity was 40% less in the CPC group than the COLL group (p = 0.045). At 60°, the AP laxity was 30% less in the CPC group, a difference that was close to statistical significance (p = 0.080). No differences were found between treatment groups with respect to the structural properties (p > 0.30). However, there were significant correlations between serum platelet concentration and AP laxity (R² = 0.643; p = 0.009), maximum load (R² = 0.691; p = 0.006), and graft stiffness (R² = 0.840; p < 0.001). In conclusion, use of a CPC to enhance healing of an allograft ACL reconstruction inversely correlated with early sagittal plane laxity and the systemic platelet count was highly predictive of ACL reconstruction graft strength and stiffness at 6 weeks. These findings emphasize the importance of further research on delineating the effect of platelets in treating of ACL injuries. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 631–638, 2009     

前交叉韧带重建术后膝关节功能及三维运动步态分析

目的 探讨前交叉韧带(ACL)重建术后膝关节稳定性、功能及三维步态运动学情况.方法 回顾性分析2015年7月到2017年7月在佛山市中医院运动学科采用自体腘绳肌腱行ACL重建并进行了二次关节镜探查的270例病例,其中男164例,女106例.采用Lysholm评分、国际膝关节评分委员会(IKDC)评分、Tenger评分、...     

Gender differences in passive knee biomechanical properties in tibial rotation

The anterior cruciate ligament (ACL) is the most commonly injured knee ligament with the highest incidence of injury in female athletes who participate in pivoting sports. Noncontact ACL injuries commonly occur with both internal and external tibial rotation. ACL impingement against the lateral wall of the intercondylar notch during tibial external rotation and abduction has been proposed as an injury mechanism, but few studies have evaluated in vivo gender‐specific differences in laxity and stiffness in external and internal tibial rotations. The purpose of this study was to evaluate these differences. The knees of 10 male and 10 female healthy subjects were rotated between internal and external tibial rotation with the knee at 60° of flexion. Joint laxity, stiffness, and energy loss were compared between male and female subjects. Women had higher laxity (p = 0.01), lower stiffness (p = 0.038), and higher energy loss (p = 0.008) in external tibial rotation than did men. The results suggest that women may be at greater risk of ACL injury resulting from impingement against the lateral wall of the intercondylar notch, which has been shown to be associated with external tibial rotation and abduction. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:937–944, 2008     

Arthrofibrosis following ACL reconstruction—reasons and outcome

Introduction Arthrofibrosis is a complication that severely influences the clinical outcome after anterior cruciate ligament (ACL) reconstruction. This retrospective clinical study analyses risk factors and outcome after arthrolysis in a large population.Material and methods Two hundred twenty-three patients who had undergone arthrolysis after ACL reconstruction were examined. Range of motion (ROM) was reduced due to arthrofibrosis of the joint in 70% (n=156). Other reasons, such as cyclops syndrome or osteoarthritis were found in 30% (n=67). The mean time interval between arthrolysis and follow-up was 4.29 years. We recorded timing of surgery, additional injuries, state of the knee before reconstruction, range of motion, pain during rehabilitation, beginning, duration and type of rehabilitation, severity and etiology of joint stiffness and the time between ACL reconstruction and revision. The present state of the knee was documented using the IKDC form.Results A significant correlation of arthrofibrosis and preoperative irritation (p<0.001), preoperative limited ROM (p=0.001), perioperative pain (p=0.046) and early beginning of muscle training (p=0.064) was found. Combination of a remaining loss of extension and development of degenerative joint disease was also significant (p=0.001). The decrease of sports activity compared with the level before ACL injury was highly significant (p<0,001). The criteria to minimize the risk of arthrofibrosis and the optimal timing of arthrolysis are pointed out.     

分期修复重建膝关节多发韧带损伤的临床疗效

目的 :探讨关节镜下分期治疗膝关节多发韧带损伤的临床疗效。方法 :2006年3月至2012年6月,关节镜下分期治疗膝关节多发韧带损伤14例(14膝)。男8例,女6例;年龄20~49岁,平均(31.8±8.1)岁。患者均行X线、MR检查,提示10例前交叉韧带、后交叉韧带及内侧副韧带损伤,4例前交叉韧带、后交叉韧带及后外侧角损伤。合并内侧半月板损伤4例,外侧半月板损伤2例。Ⅰ期手术治疗内侧副韧带损伤、后交叉韧带及半月板,术后固定3周后开始主被动功能锻炼,3~6个月后膝关节活动范围正常且存在明显松弛时Ⅱ期重建前交叉韧带和(或)后交叉韧带。结果:术后切口均Ⅰ期愈合,无感染等手术相关并发症发生。患者均获随访,时间24~80个月,平均48.9个月。末次随访时膝关节Lysholm评分达87.1±2.8,优于术前19.6±0.9(t=12.3,P0.01)。国际膝关节评分委员会(International Knee Documentation Committee,IKDC)评级:9例接近正常,5例异常。结论 :关节镜下分期治疗膝关节多发韧带损伤能有效恢复膝关节稳定性和功能。     

膝关节多发韧带损伤一期修复与重建

目的：探讨膝关节多发韧带损伤关节镜下重建前交叉韧带（anteriorcruciateligament,ACL）和后交叉韧带（posteriorcruciateligament,PCL）,及同期修复内副韧带（medialcollateralligament,MCL）、后外侧复合体（posteriorlateralcomplex,PLC）的手术方法及临床疗效。方法：2009年6月。2011年12月,30例病人（31膝）膝关节多发韧带损伤患者采用自体或同种异体肌腱关节镜下重建ACL和PCL,铆钉缝合修复内侧副韧带,铆钉缝合修复或部分股二头肌腱修复后外侧复合体,术后早期功能锻练。根据国际膝关节文献委员会（InternationalKneeDocumentationCommittee,IKDC）评分和Lysholm膝关节功能评分表对患膝功能进行评估。结果：30例病人（31膝）例随访18—30个月,平均24个月。患者在0和200应力测试时稳定性均完全恢复,IKDC评分入院时均为显著异常（D级）,术后随访时正常（A级）18例（58．0％）,接近正常（B级）10例（32．3％,）,异常（C级）3例（9．7％）。Lysholm评分由术前平均（48．7±4．5）分提高到（87．6±2．6）分,差异有统计学意义（t=-8．432,P〈0．01）。所有患者膝关节功能较术前明显改善。结论：关节镜下一期重建ACL、PCL,同期行关节外韧带修补或重建具有损伤小,能早期功能锻炼,能有效恢复关节功能,治疗效果满意。     

胫骨-股骨单隧道双束解剖重建前交叉韧带

目的探讨胫骨-股骨单隧道双束重建前交叉韧带（ACL）的近期临床效果。方法对本组2009年4月至2011年4月收治的46例ACL损伤患者进行胫骨-股骨单隧道双束解剖重建ACL,先后钻取胫骨、股骨隧道,屈膝120。由前内侧入路建立股骨隧道,之后引入双束同种异体肌腱（或自体肌腱）,肌腱胫骨端、股骨端（沿肌腱间打入钉鞘形成双束）固定,术后随访,按照IKDC和Lysholm膝关节评分标准评价疗效。结果所有患者均获得1年以上随访。最后随访时,所有患者前抽屉试验阴性,45例患者（97．8％）Lachman试验阴性,1例患者Lachman试验I度阳性。KT-1000检查显示双侧膝关节前向松弛度差值平均为（-0．47±1．39）mm,手术前后有统计学差异（t=36．07,P〈0．01）;其中30例（65．2％）〈0mm,即患侧关节稳定度高于健侧;15例（32．6％）为0～2mm;1例（2．1％）〉2mm。所有患者轴移试验检查均为阴性。活动度检查发现42例伸屈活动度均正常,1例有5。屈膝欠缺,1例患者有10。屈膝欠缺,2例有5。过伸欠缺。从膝关节稳定性方面分析,45例（97．8％）IKDC评级为正常,1例（2．2％）评级为接近正常。综合分析,44例（95．7％）IKDC评级正常,2例（4．3％）为接近正常。术后IKDC膝关节主观评分为（94．9±3．7）分,Lysholm评分为（93．71±3．3）分。受伤前Tegner评分平均为7．3分,最后随访时为6．9分。结论对膝关节ACL断裂患者施行胫骨一股骨单隧道双束解剖重建,能够建立具有高度稳定性的膝关节,使所有患者获得IKDC评级正常或者接近正常的结果。     

Biomechanics of the anterior cruciate ligament and implications for surgical reconstruction

Abstract Injury to the anterior cruciate ligament (ACL) is regarded as critical to the physiological kinematics of the femoral-tibial joint, its disruption eventually causing long-term functional impairment. Both the initial trauma and the pathologic motion pattern of the injured knee may result in primary degenerative lesions of the secondary stabilisers of the knee, each of which are associated with the early onset of osteoarthritis. Consequently, there is a wide consensus that young and active patients may profit from reconstructing the ACL. Several factors have been identified as significantly influencing the biomechanical characteristics and the functional outcome of an ACL reconstructed knee joint. These factors are: (1) individual choice of autologous graft material using either patellar tendon-bone grafts or quadrupled hamstring tendon grafts, (2) anatomical bone tunnel placement within the footprints of the native ACL, (3) adequate substitute tension after cyclic graft preconditioning, and (4) graft fixation close to the joint line using biodegradable graft fixation materials that provide an initial fixation strength exceeding those loads commonly expected during rehabilitation. Under observance of these factors, the literature encourages mid-to long-term clinical and functional outcomes after ACL reconstruction.     

Proprioception in anterior cruciate ligament deficient knees and its relevance in anterior cruciate ligament reconstruction

Injury to the anterior cruciate ligament (ACL) not only causes mechanical instability but also leads to a functional deficit in the form of diminished proprioception of the knee joint. “Functional” recovery is often incomplete even after “anatomic” arthroscopic ACL reconstruction, as some patients with a clinically satisfactory repair and good ligament tension continue to complain of a feeling of instability and giving way, although the knee does not sublux on clinical testing. Factors that may play a role could be proprioceptive elements, as the intact ACL has been shown to have significant receptors. Significant data have come to light demonstrating proprioceptive differences between normal and injured knees, and often between injured and reconstructed knees. ACL remnants have been shown to have proprioceptive fibers that could enhance functional recovery if they adhere to or grow into the reconstructed ligament. Conventionally the torn remnants are shaved off from the knee before graft insertion; modern surgical techniques, with remnant sparing methods have shown better outcomes and functional recovery, and this could be an avenue for future research and development. This article analyzes and reviews our understanding of the sensory element of ACL deficiency, with specific reference to proprioception as an important component of functional knee stability. The types of mechanoreceptors, their distribution and presence in ACL remnants is reviewed, and suggestions are made to minimize soft tissue shaving during ACL reconstruction to ensure a better functional outcome in the reconstructed knee.     

Tibiofemoral cartilage contact biomechanics in patients after reconstruction of a ruptured anterior cruciate ligament

We investigated the in vivo cartilage contact biomechanics of the tibiofemoral joint in patients after reconstruction of a ruptured anterior cruciate ligament (ACL). A dual fluoroscopic and MR imaging technique was used to investigate the cartilage contact biomechanics of the tibiofemoral joint during in vivo weight‐bearing flexion of the knee in eight patients 6 months following clinically successful reconstruction of an acute isolated ACL rupture. The location of tibiofemoral cartilage contact, size of the contact area, cartilage thickness at the contact area, and magnitude of the cartilage contact deformation of the ACL‐reconstructed knees were compared with those previously measured in intact (contralateral) knees and ACL‐deficient knees of the same subjects. Contact biomechanics of the tibiofemoral cartilage after ACL reconstruction were similar to those measured in intact knees. However, at lower flexion, the abnormal posterior and lateral shift of cartilage contact location to smaller regions of thinner tibial cartilage that has been described in ACL‐deficient knees persisted in ACL‐reconstructed knees, resulting in an increase of the magnitude of cartilage contact deformation at those flexion angles. Reconstruction of the ACL restored some of the in vivo cartilage contact biomechanics of the tibiofemoral joint to normal. Clinically, recovering anterior knee stability might be insufficient to prevent post‐operative cartilage degeneration due to lack of restoration of in vivo cartilage contact biomechanics. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1781–1788, 2012     

Comparison of outcome after ACL reconstruction in terms of subjective assessment of symptoms and function and clinical assessment of ligament stability

Background

The knee joint is frequently involved in sports and other injuries with Anterior cruciate ligament being a very common ligament to be injured. The Lachman test, pivot-shift test, and instrumented knee laxity examination are frequently used and reported for evaluation of ACL reconstruction. The aim of this study is to examine and evaluate the relationships between the clinical assessment of ligament stability and subjective assessment of symptoms and function after ACL reconstruction.

Anterolateral rotational knee instability: role of posterolateral structures

Introduction The aim of this study was to determine the anterolateral rotational instability (ALRI) of the human knee after rupture of the anterior cruciate ligament (ACL) and after additional injury of the different components of the posterolateral structures (PLS). It was hypothesized that a transsection of the ACL will significantly increase the ALRI of the knee and furthermore that sectioning the PLS [lateral collateral ligament (LCL), popliteus complex (PC)] will additionally significantly increase the ALRI. Materials and methods Five human cadaveric knees were used for dissection to study the appearance and behaviour of the structures of the posterolateral corner under anterior tibial load. Ten fresh-frozen human cadaver knees were subjected to anterior tibial load of 134 N and combined rotatory load of 10 Nm valgus and 4 Nm internal tibial torque using a robotic/universal force moment sensor (UFS) testing system and the resulting knee kinematics were determined for intact, ACL-, LCL- and PC-deficient (popliteus tendon and popliteofibular ligament) knee. Statistical analyses were performed using a two-way ANOVA test with the level of significance set at P < 0.05. Results Sectioning the ACL significantly increased the anterior tibial translation (ATT) and internal tibial rotation under a combined rotatory load at 0 and 30° flexion (P < 0.05). Sectioning the LCL further increased the ALRI significantly at 0°, 30° and 60° of flexion (P < 0.05). Subsequent cutting of the PC increased the ATT under anterior tibial load (P < 0.05), but did not increase the ALRI (P > 0.05). Conclusion The results of the current study confirm the concept that the rupture of the ACL is associated with ALRI. Current reconstruction techniques should focus on restoring the anterolateral rotational knee instability to the intact knee. Additional injury to the LCL further increases the anterior rotational instability significantly, while the PC is less important. Cautions should be taken when examining a patient with ACL rupture to diagnose injuries to the primary restraints of tibial rotation such as the LCL. If an additional extraarticular stabilisation technique is needed for severe ALRI, the technique should be able to restore the function of the LCL and not the PC. This study is a winner of the AGA DonJoy Award 2006.     

Quadrupled bone-semitendinosus ACL reconstruction: a prospective clinical investigation in 100 patients

Abstract The hypothesis of our study was that a quadrupled bonesemitendinosus tendon graft could combine the advantage of bone-tobone healing with the high cross-sectional area of a quadrupled hamstring graft in ACL reconstruction. ACL reconstruction with a semitendinosus tendon graft was performed on 100 patients with isolated ACL injury from January 1996 to December 1999: femoral fixation was obtained with Endobutton and tibial fixation with Fastlok. Patients were evaluated for standard knee scores and functional strength tests, postoperative pain rating, knee radiographs taken after surgery and at final follow-up, magnetic resonance images at 3 and 6 months, isokinetic flexion-extension and internal-external rotation tests at 3, 6, and 12 months. Computerized laxity analysis was performed at final evaluation. Average surgical time was 85 minutes, including 13 minutes for graft preparation; 90% of the patients were discharged within 24 h. Subjective knee rating was 80%; kneeling test was positive in 7% and Werner score was 44 (range, 30–48). Lachman test was negative in 90% at final evaluation (mean follow-up, 38 months). Sensory changes at the anterior part of the proximal tibia were present in 30% at 3 months and 10% had definite hyposthesia. MRI showed graft incorporation at 3 months. Computerized laxity analysis revealed 90% with less than 3-mm side-to-side differences. Isokinetic testing showed normal hamstring and quadriceps peak torques at 12 months. The functional strength tests were normal by 6 months. Average Noyes score was 87.9, Lysholm score 93, and Tegner activity rating 6.0 (pre-injury, 6.1). IKDC score showed 90 normal or nearly normal knees, 9 abnormal, and one severely abnormal knee. Quadrupled bone-semitendinosus is a viable graft for ACL reconstruction and should be considered, especially in patients with pre-existing extensor mechanism problems.