Purpose: To determine if it is necessary to assess instability of the chronic anterior cruciate ligament deficient knee under general anaesthesia. Materials and methods: 27 anterior cruciate ligament deficient knees in 27 patients were evaluated both subjectively using the Lachmanns and pivot shift test and objectively using the KT 1000 arthometer. This was done in the preoperative clinic (without the patient anaesthetised) and subsequently in the anaesthetic room with the patient anaesthetised (under general anaesthesia) prior to anterior cruciate ligament reconstruction. The data was prospectively collected. Only data on 21 knees was available for analysis. There were 20 females and one male with an average age of 29 years. Results: There was no statistical significant difference (using students T test) between the data collected using the KT 1000 arthometer with and without the patient anaesthetised. A significant difference was noted both for the Lachmanns (p< 0.01) and pivot shift test (p< 0.001) between the results obtained with and without anaesthesia. This however did not change the management. Conclusion: Assessing the chronic anterior cruciate ligament deficient knee using the KT 1000 arthrometer, Lachmann and pivot shift test under general anaesthesia is not necessary if these assessments have been carried out in clinic

Introduction and Aims: Since existing data relating to the kinematics of ACL-deficient knee joints relates mainly to walking, the kinematics during more dynamic activities remains unknown; therefore, the aim of this unique study was to describe in vivo ACL-deficient knee kinematics and muscle activity during running and cutting. Method: Fifteen subjects with proven unilateral ACL rupture were measured performing running and cutting tasks prior to surgical reconstruction. Gait analysis was used to determine inter-limb differences in displacements at the knee joint during stance phase. Simultaneous EMG analysis was performed to give temporal measures of lower limb muscle activity. Results: No significant inter-limb difference was seen for tibio-femoral translation in the sagittal or coronal planes during any part of stance phase. The ACLD limb showed a significantly reduced maximum knee flexion angle (40.4 vs. 44.0 degrees) compared to the ACL-intact (ACLI) limb (p=0.04). Internal tibial rotation was significantly greater (7.3 vs. 0.7 degrees) in the ACLD limb at toe-off (p=0.03). The quadriceps muscle group was found to be active for a significantly greater percentage of stance phase in the ACLD limb compared to the ACLI limb (p=0.001). Conclusion: The ACL-deficient gait involves consistently greater knee extensor activity than ACL-intact gait during running, and as a consequence maximum knee flexion angle is reduced. These findings contrast with the description of ‘quadriceps-avoidance’ gait often described for ACL-deficient subjects. ACL-deficient gait also demonstrates increased rotational instability during terminal stance phase

Using roentgen stereophotogrammetry we have recorded the three-dimensional movements of the knee during an anteroposterior laxity test in 36 patients with torn anterior cruciate ligaments and in three cadaver knees. At 30 degrees of knee flexion and before loads were applied the tibia occupied a more laterally rotated position if the anterior cruciate ligament had been injured. When the tibia was pulled anteriorly knees with cruciate deficiency rotated more laterally and were more abducted than normal knees. Posterior traction induced lateral rotation in the injured knee and medial rotation in the intact one. Precise knowledge of the three-dimensional instability of the anterior cruciate deficient knee may be important when the laxity is evaluated only in relation to one of the three cardinal axes

Aims

A functional anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) has been assumed to be required for patients undergoing unicompartmental knee arthroplasty (UKA). However, this assumption has not been thoroughly tested. Therefore, this study aimed to assess the biomechanical effects exerted by cruciate ligament-deficient knees with medial UKAs regarding different posterior tibial slopes.

Purposes of the study: Anterior cruciate ligament (ACL) deficiency is associated with degenerative osteoarthritis especially when it is present with meniscal injury; We assessed the impact of certain aetiological factors in chondral degeneration in the ACL deficient knee.

Methodology and Results: Fifty-eight patients who underwent consecutive primary arthroscopic anterior cruciate ligament reconstruction using the four strand hamstring graft between 10/06/2004 and 29/06/2006 were retrospectively analysed.

Patient’s charts and radiology findings were reviewed with special attention to operative notes and preoperative knee MR imaging. Patients with knee symptoms prior to presenting injury were excluded.

The mechanism of injury, the time elapsed from the original injury to anterior cruciate ligament reconstruction, associated meniscal injury, and quality of cartilage in the knee- at the time of MR imaging and ACL reconstruction were noted. Degenerative cartilage changes were graded upon reconstruction using the Outerbridge classification.

The average time from Injury to MR imaging and MR to ACL reconstruction was 4.85 and 12.65 months respectively.

We found a direct relationship between the time elapsed after the ACL injury and the severity of the chondral lesion (p< 0.05). Furthermore, a significant worsening in chondral degeneration of the involved knee was seen when the MR imaging and ACL reconstruction were more than 12 months apart (p< 0.01).

Conclusion: We conclude that chondral lesions and degeneration are more likely to be caused by an extended period of knee instability following ACL injury as opposed to age related degeneration or direct trauma to the weight bearing area of the knee.

Early reconstruction may protect the knee from chondral wear and subsequent degenerative arthritis.

We assessed proprioception using threshold levels for the perception of knee movement at slow angular velocities (0.1°/s to 0.85°/s) in 20 patients with unilateral tears of the anterior cruciate ligament (ACL) and 15 age-related control subjects. Failure to detect movement was also analysed.

The threshold levels of detection did not differ between the damaged and undamaged knees in the patients or between the patients and the control group. Failure to appreciate movement, however, was significantly greater in knees with ACL loss compared with the undamaged knees of patients and the control group.

Our findings show a proprioceptive deficit in the absence of the ACL. Measurements of threshold levels of detection of passive movement alone are not suitable for the evaluation of proprioceptive loss in ACL deficiency; assessment of failure to appreciate movement is essential.

We have assessed the biomechanical properties of a 'double-bundle' prosthetic ligament replacing the anterior cruciate in cadaver knees. We compared the results with those of single bundle 'over-the-top' and 'through-the-condyle' techniques, performing anterior drawer tests at 20 degrees and 90 degrees knee flexion. The over-the-top reconstruction gave better anteroposterior stability at 20 degrees, while the through-the-condyle repair was more stable at 90 degrees. The double-bundle reconstruction gave practically normal anterior stability at both 20 degrees and 90 degrees.

There is a recognised incidence of anterior knee pain following Anterior Cruciate Ligament (ACL) reconstruction using a patella tendon autograft.

This study examined two group of patients both pre ACL ligament reconstruction and post ACL reconstruction using patella tendon grafts to define if anterior knee pain is a result of patella tendon harvest or a primary consequence of an ACL injury.

The two groups of patients were best matched for age, sex and physical activity.

The pre-operative group of twenty-five patients had a confirmed ACL rupture and exhibited symptoms of instability requiring an ACL reconstruction.

The operative group of twenty-five patients were a minimum of a year post operation.

The graft was harvested by an open procedure and the graft bone blocks were secured with interference screws.

The patients’ anterior knee pain score was assessed using the Shelbourne scoring system that evaluates knee function in relation to anterior knee pain using five parameters. The maximum score is 100.

The scores were compared using the unpaired student test.

There was no significant age difference between the two groups, preoperative group age 32. 2 years (range 22 to 46) and postoperative age 34. 8years (range 19 to 48).

The mean anterior knee pain score for the preoperative group was 71. 6 (49 to 100), the postoperative group was 77. 7 (45 to 100), this was not significantly different.

We found no significant difference in knee function due to anterior knee pain between the two groups. Studies have shown significant anterior knee pain following hamstring reconstruction (Spicer).

This study shows anterior knee pain in the ACL deficient knee is present prior to surgery.

We conclude that patella tendon autografts produce no significant incidence of anterior knee pain post surgery.

The aim of this trial was to assess the clinical examination findings commonly used for the ACL deficient knee.

For reliability testing and criterion validation 102 patients with ACL injuries were assessed by a single observer, 35 by a second observer and 47 again by the initial observer. For construct and criterion validation 30 patients were assessed pre-operatively and a mean of 1.7 years after ACL reconstruction. The Lysholm 11, Tegner and Cincinnati outcome measures were assessed along with instrumented knee laxity (Stryker test), the one hop test (OHT) and graded tests (including anterior draw, Lachman test, quality of end point, and pivot shift test).

The outcome measures were found to be reliable except the Cincinnati system. All examination findings were of unsatisfactory reliability, with the exception of the OHT and the Stryker test. Construct validation revealed a significant improvement in all outcome measure scores and examination findings following ACL reconstruction. Criterion validation revealed that of the examination findings only the OHT had a satisfactory correlation with the symptom of giving way and the Lysholm/Tegner measures. Comparison of the difference between the desired and actual Tegner activity levels with the examination findings revealed an improvement in all levels of correlation.

With the exception of the OHT, the clinical examination findings used for the ACL deficient knee are unreliable and correlate poorly with the functional outcome of the patient. They may, however, have some benefit in assessment of deficiency of the anatomical structures and the findings should be presented individually, rather than forming part of the functional assessment of the patient.

We treated 39 knees with chronic deficiency of the anterior cruciate ligament by reconstruction using the ABC carbon and polyester prosthetic ligament; 31 (79.5%) were reviewed at an average follow-up of 34 months. There had been four complete failures requiring revision. The remaining 27 were studied in detail. On the Lysholm rating, only 11 knees (41%) had good results with a score of over 76. The mean anterior drawer movement was reduced from 7.6 mm before operation to 5.8 mm at review. The mean difference from the opposite uninjured knee was 3.9 mm before operation, 1 mm (in 21 patients) at mean follow-up of 7.4 months and 2.5 mm (in 27 patients) at 34 months, indicating progressive loss of effect. In our opinion the results are unsatisfactory: we do not recommend the use of this prosthetic ligament.

The Pivot-shift test is a clinical test for knee instability for patinets with Anterior cruciate ligament (ACL), however the test has low inter-observer reliability. Dynamic radiostereometry (dRSA) imaging is a highly precise method for objective evaluation of joint kinematics. The purpose of the study was to quantify precise knee kinematics during Pivot-shift test by use of the non-invasive dynamic RSA imaging. Eight human donor legs with hemipelvis were evaluated. Ligament lesion intervention of the ACL was performed during arthroscopy and anterolateral ligament (ALL) section was performed as a capsular incision. Pivot-shift test examination was recorded with dRSA on ligament intact knees, ACL-deficient knees and ACL+ALL-deficient knees. A Pivot-shift pattern was identifyable after ligament lesion as a change in tibial posterior drawer velocity from 7.8 mm/s in ligament intact knees, to 30.4 mm/s after ACL lesion, to 35.1 mm/s after combined ACL-ALL lesion. The anterior-posterior drawer excursion increased from 2.8 mm in ligament intact knees, to 7.2 mm after ACL lesion, to 7.6 mm after combined lesion. Furthermore a change in tibial rotation was found, with increasing external rotation at the end of the pivot-shift motion going from intact to ACL+ALL-deficient knees. This experimental study demonstrates the feasibility of RSA to objectively quantify the kinematic instability patterns of the knee during the Pivot-shift test. The dynamic parameters found through RSA displayed the kinematic changes from ACL to combined ACL-ALL ligament lesion

The purpose of the present study is to determine a correlation between articular cartilage changes and underlying bone contusions in ACL-deficient knees. Analysis of surgical and MRI findings in thirty-seven knees shows that medial femoral condyle and medial tibial plateau bone contusions, present in 30% of ACL injuries, correlate strongly with articular cartilage damage, irrespective of meniscal status. Although lateral compartment bone contusions are more commonly seen following injury, we have not found this to be associated with the status of the overlying cartilage. Degenerative changes in the ACL-deficient knee are multifactorial, but medial compartment bone contusions may be an important contributor that warrants further investigation. Despite successful reconstruction of the anterior cruciate ligament, many patients eventually develop osteoarthritis, suggesting that something in addition to mechanical instability may contribute. The purpose of the present study is to determine a correlation between articular cartilage changes and underlying bone contusions in ACL-deficient knees. Between January 2002 and March 2003, sixty-eight knees consecutively underwent ACL reconstruction at our institution. Presence and location of bone contusions on MRI were noted, and correlated to presence of articular cartilage changes and meniscal pathology witnessed during surgery. Of the sixty-eight knees operated, thirty-one were excluded because of either: pre-existing arthritis, previous surgery, presence of multiple ligament injury, or absence of bone contusions on MRI. In the analysis of the thirty-seven remaining knees, bone contusions were present on the medial tibial plateau and medial femoral condyle in 30%, on the lateral tibial plateau in 84%, and on the lateral femoral condyle in 73%. Articular cartilage damage is most commonly seen on the medial femoral condyle, irrespective of meniscal status. Analysis using Fisher’s Exact test shows that medial femoral condyle (p=0.026) and medial tibial plateau articular cartilage damage (p= 0.011) is strongly correlated with presence of underlying bone contusions. No association was found between lateral compartment articular cartilage status and presence of bone contusions. Although lateral compartment bone contusions are common following ACL injuries, we have not found an association with cartilage damage. Degenerative changes in the ACL-deficient knee are multifactorial, but medial compartment bone contusions may be an important contributor

To describe our experience with computer assisted combined anterior cruciate ligament (ACL) reconstruction and osteotomy. It may provide long-term symptom relief and improved function in patients with medial knee arthrosis and ACL-deficiency, while delaying or possibly eliminating the need for further surgical intervention such as arthroplasty. Two patients who had medial unicompartmental arthrosis and chronic ACL-deficient knees underwent ACL reconstruction along with femoral osteotomy in one case and upper tibial osteotomy in the other. We used Orthopilot software to perform computer assisted combined anterior cruciate ligament (ACL) reconstruction and osteotomy. Subjective evaluation at postoperatively indicated significant improvement compared to preoperative evaluation and better scores for patients who obtained normal knee range of motion. Objective evaluation by International Knee Documentation Committee showed improved score postoperatively. Both had minor complications occurred in the immediate postoperative period. The average correction angle of the osteotomy was 7 degrees (7–10). Computer assisted ACL reconstruction and osteotomy may provide long-term symptomatic pain relief, increased activity and improved function. Only Anterior cruciate ligament reconstruction may not effectively provide pain relief to the ACL-deficient knee with degenerative medial arthrosis. The results of this study suggest that combined high tibial or femoral osteotomy and ACL reconstructions are effective in the surgical treatment of varus, ACL-deficient knees with symptomatic medial compartment arthritis. Computer aided surgery allows precise correction of the axial deformity and tunnel orientation intraoperatively

Introduction: Instrumented arthrometry is a widely used technique for the quantification of cruciate ligament laxity. It is used both before and after surgery. The Rolimeter(Aircast, Europe) is used in such scenarios. It has several advantages over its cousins; it is more compact, lighter, less expensive and amenable to sterilization techniques. The other leading arthrometers have however had over 15 years of clinical use and their reliability has been thoroughly assessed. Muellner et al found no significant difference in the intra-tester and inter-tester results obtained on Rolimeter assessment of the knees of un-injured healthy subjects. Our study assessed the inter-tester and intra-tester variability when the Rolimeter is applied to patients with unilateral ACL-deficient knees. It also examines whether the level of experience of the examiner influences the results in this group of patients. Materials and Methods: Six examiners each examined thirty-three subjects on two occasions. One examiner was medically qualified but had never performed a Lachman or anterior drawer test. Two examiners were qualified physiotherapists who routinely examined knees, but had never used a Rolimeter. One medically qualified examiner was considered to be of intermediate experience.Two examiners were regarded as expert Rolimeter users.For each examination a Rolimeter reading was taken three times with the knee at 30 degrees of flexion and three times at 90 degrees of flexion for both knees.The interval between examinations was at least thirty minutes. All the readings were acquired on the same day. The examiners were blinded to whether the subject was known to be ACL deficient or not. The results of the examinations were entered onto a data-base.Repeated measures analysis of variance was used to test for the effects of the following factors, difference between examiners, reproduction of results between examinations. Results: There was no significant difference between each set of measures for each subject between examinations (p=0.767), indicating that the measurement procedure was reliable. Measurements were significantly higher in patients with ACL-deficient knees compared to the control group (p< 0.001) confirming the sensitivity of the Rolimeter to help diagnose ACL-deficient knees. The in-experienced examiner’s measurements were lowest and were more reliable. The examiner with the intermediate experience was the most un-reliable. Both experienced examiners were in close agreement. Conclusion: We have demonstrated that the rolimeter is reliable in the assesment of ACL deficient patients regardless of the experience of the examiner

The ACL-deficient knee demonstrates an increase in both tibial rotation and translation that can lead to progressive degeneration within the knee joint. Functional Knee Braces (FKBs) have often been prescribed as an integral part of treatment programmes for such patients. However, the ability of a FKB to increase the stability of the ACL-deficient knee by controlling tibial translation has yet to be confirmed. In addition the athlete with ACL deficiency frequently asks if he/she can use a treadmill as a safe indoor exercise tool. A prospective study was carried out on 15 pre-operative ACL-deficient patients and 15 fully matched subjects as controls. A gait analysis study was designed using the CODA mpx30 gait analysis system with electromyography (EMGs). The study was carried out using 3 gait situations - simple level walking and treadmill walking (3.6 km/h) both representing low physical activity and treadmill running (10 km/h) representing high physical activity. The tempero-spatial parameters, total range of motion (ROM), joint positions and EMGs were recorded with and without the FKB and the results were compared with the baseline data of both the patients and the data derived from the control subjects. ACL-deficient subjects had significantly lower speed, shorter stride length and consequently longer double support time while walking on level ground (p< 0.05). None of these variables changed following bracing. The ACL-deficient subjects showed more knee flexion at heel strike and mid-stance which was assumed to be a compensatory reaction to the ligament deficient knee. The FKB significantly reduced ROM in the ACL-deficient subjects at all gait activity levels (p< 0.05). It also reduced peak knee flexion during swing while walking on level ground, but increased maximum knee flexion in swing while walking on the treadmill. Walking on the treadmill reduced hip ROM but running on the treadmill increased ankle ROM in both groups of subjects. No significant angulatory kinematic changes were found during running on the treadmill either before or after bracing. The ACL-deficient subjects showed more knee rotation than the controls during all the trials. Neither the quadriceps nor hamstring muscles showed significant differences between the ACL-deficient and control subjects. The gastrocnemius muscle however was found to have a principal role in the ACL-deficient subjects. FKBs caused the gastrocnemius to be activated earlier (P=0.0001) and showed a positive effect during low force activities. As treadmill walking or running was always accompanied by an increased ankle plantar flexion, it always decreased the gastrocnemius onset activation time that may be a compensatory reaction to stabilise the injured knee. No significant differences were found between the ACL-deficient and the control subjects in terms of kinematics or EMG findings during running on the treadmill. We have identified beneficial biomechanical changes following the use of FKBs on ACL-deficient knees but only during walking trials. The brace was as effective for walking on the treadmill as walking on the ground. The FKBs led the deficient knees into a safer kinematics and EMG pattern. The ACL-deficient subjects ran as normally as the control subjects and no effects of the FKBs were found during running in our studies

The anterolateral ligament (ALL) has been recently recognized as a distinct stabilizer for internal rotation in the ACL-deficient knee and it has been hypothesized that ALL reconstruction may play an important role in improving anterolateral instability following ACL reconstruction. Both the gracilis tendon (GT) and a portion of the iliotibial band (ITB) have been suggested as graft materials for ALL reconstruction, however, there is an ongoing debate concerning whether GT or ITB are appropriate grafting materials. Furthermore, there is limited knowledge in how the mechanical properties of these potential grafts compare to the native ALL. Consequently, the aim of this study was to characterize the elastic (Young's modulus and failure load) and viscoelastic (dynamic and static creep) mechanical properties of the ALL and compare these results with the characteristics of the grafting materials (GT and ITB), in order to provide guidance to clinicians with respect to graft material choice. Fourteen fresh-frozen cadaveric knees (85.2±12.2 yr) were obtained. The ALL, ITB, and the distal (GTD) and proximal gracilis tendons (GTP) (bisected at mid portion) were harvested from each donor and tested with a dynamic material testing frame. Prior to testing, the cross-sectional area of each tissue was measured using a casting method and the force required to achieve a min-max stress (1.2–12 MPa) for the testing protocol was calculated (preconditioning (20 cycles, 3–6 MPa), sinusoidal cycle (200 cycles, 1.2–12 MPa), dwell at constant load (100 s, 12 MPa), and load to failure (3%/s)). Kruskall-Wallis tests were used to compare all tissue groups (p<0.05). The Young's modulus of both ALL (181.3±63.9 MPa) and ITB (357.6±94.4 MPa) are significantly lower than GTD (835.4±146.5 MPa) and GTP (725.6±227.1 MPa). In contrast, the failure load of ALL (124.5±40.9 N) was comparable with GTD (452.7±119.3 N) and GTP (433±133.7 N), however, significantly lower than ITB (909.6±194.7 N). Dynamic creep of the ALL (0.5±0.3 mm) and ITB (0.7±0.2 mm) were similar (p>0.05) whereas the GTD (0.26±0.06 mm) and GTP (0.28±0.1 mm) were significantly lower. Static creep progression of the ALL (1.09±0.4 %) was highest across all tissues, while GTD (0.24±0.05 %) and GTP (0.25±0.0.04 %) were lowest and comparable with ITB (0.3±0.07 %) creep progression. Since grafts from the ITB, GTD and GTP were comparable to the ALL only for certain mechanical properties, there was no clear preference for using one over another for ALL reconstruction. Therefore, further studies should be performed in order to evaluate which parameters play a vital role to determine the optimum grafting choice

We used single-photon emission computed tomography (SPECT) to determine the long-term risk of degenerative change after reconstruction of the anterior cruciate ligament (ACL). Our study population was a prospective series of 31 patients with a mean age at injury of 27.8 years (18 to 47) and a mean follow-up of ten years (9 to 13) after bone-patellar tendon-bone reconstruction of the ACL. The contralateral normal knee was used as a control. All knees were clinically stable with high clinical scores (mean Lysholm score, 93; mean Tegner activity score, 6). Fifteen patients had undergone a partial meniscectomy and ACL reconstruction at or before reconstruction of their ACL. In the group with an intact meniscus, clinical symptoms of osteoarthritis (OA) were found in only one patient (7%), who was also the only patient with marked isotope uptake on the SPECT scan compatible with OA. In the group which underwent a partial meniscectomy, clinical symptoms of OA were found in two patients (13%), who were among five (31%) with isotope uptake compatible with OA. Only one patient (7%) in this group had evidence of advanced OA on plain radiographs. The risk of developing OA after ACL reconstruction in this series is very low and lower than published figures for untreated ACL-deficient knees. There is a significant increase (p < 0.05) in degenerative change in patients who had a reconstruction of their ACL and a partial meniscectomy compared with those who had a reconstruction of their ACL alone

BACKGROUND. UKA is functionally superior to TKA, with kinematics similar to native knees, nevertheless, UKA implants are used in less than 10% of cases. While advantages of UKA are recognized, ACL-deficiency is generally considered a contraindication. The hypothesis of this study was that fix bearing UKA in ACL-deficient knees, with appropriate adaptation of implant placement, would result in similar kinematic trends to conventional UKA with an intact ACL. METHODS. Ten conventional UKA patients were compared to eight patients with the same implant but a deficient ACL. A 50% tibial slope reduction was applied to compensate for instability resulting from the deficient ACL. Knee kinematics were evaluated using a moving fluoroscope allowing to track the knee joint during deep knee bend, level walking, ramp descent and stair descent. The results were further compared to six TKA patients. RESULTS. During standing, a posterior shift of the femur was observed for the ACL-deficient UKA patients compared to conventional UKA patients. This posterior shift was also present during the first 25% of deep knee bend. Most parameters revealed no difference in range of motion across all activities between the two UKA groups. This is in contrast to TKA patients showing different motion trends and decreased range of motion. CONCLUSIONS. Despite the posterior femoral shift due to ACL-deficiency, both UKA groups showed similar kinematic trends, indicating that posterior tibial slope reduction can partially compensate for ACL function. This confirmed our hypothesis that fix bearing UKA can be a viable treatment option for selected ACL-deficient patients

Recent reports have suggested an increase in the number of anterior cruciate ligament (ACL) injuries in children, although their true incidence is unknown. The prognosis of the ACL-deficient knee in young active individuals is poor because of secondary meniscal tears, persistent instability and early-onset osteoarthritis. The aim of surgical reconstruction is to provide stability while avoiding physeal injury. Techniques of reconstruction include transphyseal, extraphyseal or partial physeal sparing procedures. In this paper we review the management of ACL tears in skeletally immature patients. . Cite this article: Bone Joint J 2013;95-B:1562–9

Aims

The aim of this study was to compare a bicruciate-retaining (BCR) total knee arthroplasty (TKA) with a posterior cruciate-retaining (CR) TKA design in terms of kinematics, measured using fluoroscopy and stability as micromotion using radiostereometric analysis (RSA).