Augmentation technique for partial ACL ruptures using semitendinosus tendon in the over-the-top position

The aim of this study is to present a surgical augmentation technique for partial ACL ruptures in which an isolated, autologous, double-bundle semitendinosus tendon graft is passed over the top of the femur, thus fully preserving the still-intact fibers of the ligament remnant. Between 1992 and 2006, 24 patients underwent ACL semitendinosus autograft reconstruction and were followed up for at least 2 years. The median follow-up was 6.2 years (2–15.6). At the last follow-up examination, the patients were evaluated using the International Knee Documentation Committee scale. Subjective and functional parameters were assessed using the Tegner activity scale and the Lysholm scale. Instrumental evaluation was carried out using the KT-1000 instrument. Sixteen of the 24 patients achieved an IKDC score of A. Of the remaining eight patients, six achieved an IKDC score of B, one an IKDC score of C, and one an IKDC score of D. According to the Tegner activity scale, the median pre-injury sports activity level was seven (5–9) and the median post-injury level was six (4–9), while the mean Lysholm scale score was 95 (90–100). Clinical and biomechanical studies have shown that reconstruction techniques that address both bundles of the ACL provide better rotational stability than techniques that address only a single bundle. Therefore, it seems logical than in patients with a partial rupture of the ACL, the intact bundle could be preserved and only the torn bundle would need to be reconstructed.     

Selective anteromedial bundle reconstruction in partial ACL tears: a series of 36 patients with mean 24 months follow-up

The purpose of this study was to describe an original technique of reconstruction of the anteromedial bundle preserving the posterolateral bundle and to report the results of a consecutive 36 patients series with mean 24 months follow-up. Our hypothesis is that this selective reconstruction of ACL partial tears could restore knee stability and function. In a consecutive series of 256, ACL reconstructions, 36 patients in which intact ACL fibers remained in the location corresponding to the posterolateral bundle were perioperatively diagnosed. These patients (21 women and 15 men) underwent isolated reconstruction of the anteromedial bundle while keeping the remaining fibers intact. AM bundle reconstructions were performed by the same surgeon using an outside-in technique. A quadrupled hamstring graft was used in 20 patients and a doubled semitendinosus graft in 16 patients. The mean age of the patients at the time of surgery was 32 years (min 15, max 53). The delay between injury and surgery was 6.6 months (min 2, max 35). Patients were assessed with the IKDC ligament evaluation form. Instrumented knee testing was performed with the Rolimeter arthrometer. Statistical analysis was performed to compare the preoperative and postoperative objective evaluation. Eleven concomitant meniscal lesions at the time of reconstruction were found. One patient who underwent a traumatic graft rupture at 4 months post surgery and two patients with previous contralateral ACL reconstruction were excluded, leaving 33 patients for final evaluation. Three reoperations were performed, including two arthrolysis for cyclops syndrome and one revision for a traumatic graft rupture. At last follow-up, 24 (73%) patients were graded A, 8 (24%) graded B and 1 C (3%) at IKDC objective evaluation. Mean side to side instrumented laxity was 4.8 mm (min 3, max 6) preoperatively and 0.8 mm (min 0, max 2) postoperatively. AM bundle reconstruction with an outside-in technique remains simple and reproducible. The preliminary results are encouraging with excellent side to side laxity. Graft size should probably be adapted to limit cyclops syndrome occurrence.     

MR imaging of anterior cruciate ligament reconstruction poor outcomes

Purpose

Is to study the diagnostic value of MR imaging in assessment of poor outcomes of ACL reconstruction using second look arthroscopy of the knee as a gold standard.

Patients and methods

51 patients were included in this study who did ACL reconstruction followed by MRI and second look arthroscopy. Arthroscopy study was performed within 7–15 days from MR examination. The time interval between ACL reconstruction and MRI examination was 10 months to 9 years. MR images were evaluated for; (1) ACL graft failure assessing the primary and secondary signs, (2) Tibial and femoral tunnel location, and (3) Complication of ACL graft reconstruction. MR imaging results were compared with the arthroscopic results.

Results

Second look arthroscopy revealed 23 patients with full- thickness ACL graft tears, 17 partial -thickness ACL graft tears and 11 intact ACL grafts. Complete ACL graft discontinuity, focal ACL graft thinning and preserved 100% graft thickness were the most valuable primary MRI signs in the diagnosis of full thickness ACL graft tear, partial tear and intact graft respectively.

Conclusion

We found MR imaging to be reliable for the evaluation of ACL graft poor outcomes including graft failure and complications.     

KT-1000 records smaller side-to-side differences than radiostereometric analysis before and after an ACL reconstruction

The KT-1000 and similar non-invasive arthrometers are used as a complement to clinical examination in the diagnosis of anterior cruciate ligament (ACL) rupture and during the follow-up after surgery. We compared the two methods, KT-1000 and Radiostereometric analysis (RSA), when used to measure anterior-posterior knee laxity (A-P laxity) in patients with ACL rupture, before and after the reconstruction of this ligament, in a prospective, comparative study. Twenty-two consecutive patients (14 men, 8 women) with a median age of 24 years (range 16–41) were studied. All the patients had a unilateral ACL rupture and an intact contralateral knee. The patients were operated on by one experienced surgeon using the bone-patellar tendon-bone (BTB) autograft. Preoperatively and 2 years after the reconstruction, all the patients were evaluated using KT-1000 and RSA measurements of A-P laxity. The side-to-side differences between the injured and the intact knees, that is, total A-P laxity for both knees, are presented. Preoperatively, the median side-to-side differences using the two methods (KT-1000/RSA) were 4.0 (0–10)/7.4 mm (2.2–17.4) (P<0.0001). The total A-P laxity on the injured side was 11.0 (6.0–18.0)/10.9 mm (6.2–19.6) (n.s), while it was 8.0 (6.0–10.0)/3.1 mm (0.2–8.6) on the intact side (P<0.0001). A side-to-side difference of more than 3.0 mm was defined as the cut-off value for indicating ACL rupture. Using the KT-1000, 11 of 22 (50%) patients had a cut-off value above 3.0 mm, while the corresponding figure for RSA was 21/22 (95%) patients. At the 2-year follow-up, the median side-to-side differences using the two methods (KT-1000/RSA) were 0.5 (−1.5 to 4.0)/2.8 mm (−1.8 to 10.7) (P<0.0001). The total A-P laxity on the operated side was 9.5 (7.5–14.0)/6.5 mm (2.4–14.1) (P<0.0001). We conclude that the KT-1000 recorded significantly smaller side-to-side differences than did the RSA, both before and after the reconstruction of the ACL using a BTB autograft. Before it was mainly an effect of larger A-P laxity recordings with KT-1000 on the intact side, and after the reconstruction, the KT-1000 still recorded larger A-P laxity on the intact side and also larger A-P laxity on the reconstructed side than RSA.     

Validation of the position of the femoral tunnels in anatomic double-bundle ACL reconstruction with 3-D CT scan

This study compares the positioning of femoral AM and PL tunnels obtained with specific ancillary instruments during anatomic double-bundle ACL reconstruction with the native ACL footprint using three-dimensional computed tomography (3-D CT). In 35 consecutive patients, anatomic double-bundle ACL reconstruction was performed with specific ancillary instruments. Three-dimensional CT reconstruction of both knees was performed using the volume rendering technique. In the controls (contralateral knee, with intact ACL), the angle between the longitudinal axis of the footprint and the axis of the femur, the “footprint angle” (FA) was measured. On the involved side, using the axis passing through the tunnel centers, FA was also measured. In both the groups, footprint’s length and width, and distances to cartilage margins were measured. FA was 28.1° ± 5.0° in the controls and 32.9° ± 15.8° on the involved side (n.s.). There was no statistical difference between the two groups for the other morphometric parameters: footprint’s length and width, and distances to cartilage margins. Using specific ancillary instruments the morphometric parameters of the reconstructed femoral ACL footprint were similar to the native ACL.     

Arthroscopic intra- and extra-articular anterior cruciate ligament reconstruction with gracilis and semitendinosus tendons

Numerous surgical procedures have been developed and used for anterior cruciate ligament (ACL) reconstruction. Patellar tendon is probably the most common graft used, but gracilis and semitendinous tendons present some interesting advantages: small incision, large graft when doubled, characteristics close to ACL, rapid harvest. We describe a combined intra- and extra-articular arthroscopic ACL reconstruction using hamstring tendons which includes some original steps. The tendons are harvested, leaving the distal insertion intact, and sutured together. After drilling of the tibial tunnel, an over-the-top arrangement is formed, creating a groove in the posterolateral aspect of the femur. The tendons are then fixed with double staples in the groove, and their remaining part is fixed distally to Gerdy’s tubercle passing under the fascia, but over the lateral collateral ligament (LCL). This technique ensures sufficient strength in the graft and permits correction of any associated instability, because of the presence of the extra-articular portion of the tendons. Furthermore, the over-the-top arrangement reduces trauma and possible pitfalls related to tunnel construction and permits isometry of the extra-articular portion to be established. Forty patients involved in sports activity were prospectively selected and evaluated at a minimum 2 years’ follow-up. IKDC score and Lysholm score were used for clinical evaluation, and the KT-2000 was used for instrumental laxity measurements. Resumption of sport and time to that point were recorded as well as Tegner activity score. We had 92.5% normal and fairly normal knees according to IKDC score and only 7.5% abnormal knees. Mean Lysholm score was 95. Mean Tegner score was 7.2. KT-2000 showed a mean injured/uninjured difference of 2.1 mm. In all, 90% of patients resumed sports at the same level, 67.5% in 3–4 months and 27.5% in 4–6 months. The highly satisfactory results of this series with no major complications confirm the reliability of this techinque and the possibility of guaranteeing functional behaviour in the knee. Received: 5 April 1997 Accepted: 25 July 1997     

Biomechanical evaluation of using one hamstrings tendon for ACL reconstruction: a human cadaveric study

Harvesting both the semitendinosus and gracilis tendons for anterior cruciate ligament (ACL) reconstruction has a negative impact on muscle strength as well as knee function and stability. With a new “All-inside” technique, using only one hamstrings tendon (semitendinosus or gracilis) is possible because of a reduction in length requirements. The research question of this in vitro study was whether the use of only one hamstrings tendon (semitendinosus or gracilis) could restore knee kinematics and in situ force in the ACL to the level of an intact knee. Ten human cadaveric knees were tested in the following conditions: (1) intact, (2) ACL-deficient, and (3) ACL reconstruction with the “All-inside” technique using the (a) single semitendinosus tendon graft, or (b) single gracilis tendon graft. Using a robotic testing system, external loads, i.e. (1) an anterior tibial load of 134-N and (2) combined rotatory loads of 10-Nm valgus and 5-Nm internal tibial torques, were applied. The multiple degrees of freedom knee kinematics and the in situ forces in the ACL and ACL grafts were determined. In response to a 134-N anterior tibial load, the use of either graft could restore anterior tibial translation to within 1.3 mm of the intact knee. The in situ forces in the two grafts were not significantly different from those of the intact ACL. Under the combined rotatory loads, both grafts could restore knee kinematics as well as the in situ force in the grafts to the level of the intact ACL. The “All-inside” technique using either the semitendinosus or gracilis tendon for ACL reconstruction could satisfactorily restore time-zero knee kinematics and the in situ forces in either graft to those for the intact ACL, supporting clinical findings.     

Clinical experience with PDS II augmentation for operative treatment of acute proximal ACL ruptures – 2-year follow-up

The results of prospective anterior cruciate ligament (ACL) refixation in 33 patients with high proximal rupture is reported at 20– 28 months’ follow-up: mean age was 31.1 ± 12.5 years. The surgical technique was a specially developed refixation of the ACL using a multiple suture loop (modified Marshall technique) augmented with intra-articular PDS II (polydioxanon, resorbable, Ethicon, Hamburg, Germany) to avoid derangement of blood circulation and to guarantee early functional rehabilitation. All patients were operated on within 7.3 ± 4.5 days after injury. According to the IKDC evaluation score, 22 patients showed excellent and 10 patients good subjective function. Twenty regained their pre-injury level of activity. Anterior stability was tested manually and by KT-1000 max (Medmetric, San Diego). Twenty-eight patients had a firm end-point, although there was a positive Lachman test in 16 patients. Maximal joint laxity as measured by KT-1000 showed a 1–2 mm, 3–5 mm, 6–10 mm and > 10 mm anterior drawer for 16, 14, 2 and 1 patients, respectively. Twenty-five of the evaluated knee joints had a negative pivot shift test. Three patients had a limited range of motion. The potential advantages of PDS II-augmented refixation of acute proximal ACL ruptures are anatomic reconstruction without destruction of other anatomic structures used as grafts, early functional rehabilitation and possibly better proprioception. Received: 6 March 1998 Accepted: 10 June 1998     

The “Lever Sign”: a new clinical test for the diagnosis of anterior cruciate ligament rupture

Purpose

A new clinical test for the diagnosis of ACL rupture is described: the so-called “Lever Sign”. This prospective study on four groups of patients divided subjects on the basis of MRI findings (complete or partial ACL lesion) and the clinical phase of the injury (acute or chronic). The hypothesis was that this manual test would be diagnostic for both partial and complete tears of the ACL regardless of the elapsed time from injury.

Methods

A total of 400 patients were evaluated and divided into four, equal-sized groups based on time elapsed from injury and MRI findings: Group A (acute phase with positive MRI for complete ACL rupture), Group B (chronic phase with positive MRI for complete ACL rupture), Group C (acute phase with positive MRI for partial ACL rupture), and Group D (chronic phase with positive MRI for partial ACL rupture). Clinical assessment was performed with the Lachman test, the Anterior Drawer test, the Pivot Shift test, and the Lever Sign test. The Lever Sign test involves placing a fulcrum under the supine patient’s calf and applying a downward force to the quadriceps. Depending on whether the ACL is intact or not, the patient’s heel will either rise off of the examination table or remain down. Additionally, the Lever Sign test was performed on the un-injured leg of all 400 patients as a control.

Results

All tests were nearly 100 % sensitive for patients with chronic, complete tears of the ACL. However, for patients with acute, partial tears, the sensitivity was much lower for the Lachman test (0.42), Anterior Drawer test (0.29), and Pivot Shift test (0.11), but not the Lever Sign test (1.00).

Conclusion

In general, chronic, complete tears were most successfully diagnosed but acute, partial tears were least successfully diagnosed. The Lever Sign test is more sensitive to correctly diagnosing both acute and partial tears of the ACL compared with other common manual tests. The clinical relevance is that some ACL ruptures may be more accurately diagnosed.

     

Meniscal repair using the FasT-Fix device in patients with chronic meniscal lesions

The aim of this prospective study was to evaluate meniscal suturing using the FasT-Fix device for chronic meniscal tears. This procedure was carried out on 25 patients between 2006 and 2007. Nineteen patients were male and the median age was 31 (14–47) years. The median waiting time to surgery was 27 (6–80) months and the median follow-up was 20 (14–29) months. Eleven patients (44%) required reconstruction of an associated anterior cruciate ligament (ACL) injury. 20 patients (80%) showed medial meniscus tears. All tears were located in the red zone or red–white zone. According to Barett’s criteria, meniscal tear healing was achieved in 21 patients (84%). Lysholm and Tegner scale scores improved from 60 (47–77) preoperatively to 95 (58–100) postoperatively and from 3 (2–6) preoperatively to 6 (3–9) postoperatively, respectively. There were no neurovascular complications. Revision surgery was necessary in one patient, in whom a partial meniscectomy was performed. The results obtained suggest that chronic meniscal tears in the zones described can be healed.     

Outcome and knee-related quality of life after anterior cruciate ligament reconstruction: a long-term follow-up

The aim of the present investigation was to study patient-reported long-term outcome after anterior cruciate ligament (ACL) reconstruction. On an average 11.5 years after ACL reconstruction with bone-patellar tendon-bone (BPTB) autograft 56 patients were asked to answer four different questionnaires about their knee function and knee-related quality of life. Another aim was to study whether there were any correlations between clinical tests, commonly used for evaluating patients with ACL injuries, which were performed 2 years after ACL reconstruction, and patient-reported outcome in terms of knee function and knee-related quality of life on an average 9.5 years later. All patients who had unilateral BPTB ACL reconstructions were examined at 2 years and on an average 11.5 years after surgery. At 2 years one-leg hop test for distance, isokinetic muscle torque measurement, sagittal knee laxity, Lysholm knee scoring scale and Tegner activity scale were used for clinical evaluation. At the follow-up on an average 9.5 years later the patients were evaluated with knee injury osteoarthritis outcome score (KOOS), short form health survey (SF 36), Lysholm knee scoring scale and Tegner activity scale. The SF-36 showed that the patients had a similar health condition as an age- and gender-matched normal population in Sweden on an average 11.5 years after ACL reconstruction. There was no correlation between the results of one-leg hop test for distance, isokinetic muscle torque measurement, sagittal knee laxity evaluated 2 years after surgery and the result of KOOS (function in sport and recreation, knee-related quality of life) and SF-36 evaluated on an average 11.5 years after surgery. We also compared patients that 2 years after surgery demonstrated a side-to-side difference in anterior–posterior knee laxity of more than 3 mm with those with 3 mm or less and found no significant group differences in terms of knee function as determined with KOOS. We found no correlation between the results of KOOS and SF-36 at the long-term follow-up and the time between injury and surgery, age at surgery or gender, respectively. We conclude that there is no correlation between patient-reported knee function in sport and recreation and knee-related quality of life on an average 11.5 years after BPTP ACL reconstruction and the evaluation methods used 2 years after surgery.     

Evaluation of the tunnel placement in the anatomical double-bundle ACL reconstruction: a cadaver study

The objective of this study was to investigate the accurate AM and PL tunnel positions in an anatomical double-bundle ACL reconstruction using human cadaver knees with an intact ACL. Fifteen fresh-frozen non-paired adult human knees with a median age of 60 were used. AM and PL bundles were identified by the difference in tension patterns. First, the center of femoral PL and AM bundles were marked with a K-wire and cut from the femoral insertion site. Next, each bundle was divided at the tibial side, and the center of each AM and PL tibial insertion was again marked with a K-wire. Tunnel placement was evaluated using a C-arm radiographic device. For the femoral side assessment, Bernard and Hertel’s technique was used. For the tibial side assessment, Staubli’s technique was used. After radiographic evaluations, all tibias’ soft tissues were removed with a 10% NaOH solution, and tunnel placements were evaluated. In the radiographic evaluation, the center of the femoral AM tunnel was placed at 15% in a shallow–deep direction and at 26% in a high–low direction. The center of the PL bundle was found at 32% in a shallow–deep direction and 52% in a high–low direction. On the tibial side, the center of the AM tunnel was placed at 31% from the anterior edge of the tibia, and the PL tunnel at 50%. The ACL tibial footprint was placed close to the center of the tibia and was oriented sagittally. AM and PL tunnels can be placed in the ACL insertions without any coalition. The native ACL insertion site has morphological variety in both the femoral and tibial sides. This study showed, anatomically and radiologically, the AM and PL tunnel positions in an anatomical ACL reconstruction. We believe that this study will contribute to an accurate tunnel placement during ACL reconstruction surgery and provide reference data for postoperative radiographic evaluation.     

Simultaneous bilateral anterior cruciate ligament reconstruction: a safe option

When patients present with bilateral anterior cruciate ligament (ACL) deficiency and require reconstruction in both knees, a single setting or staged approach can be adopted. Although single-setting reconstruction has been described, there are no published case series that describe simultaneous bilateral ACL reconstruction. We report a case series of eight patients who underwent simultaneous bilateral ACL reconstruction. We used two-camera stack systems to allow for truly simultaneous bilateral surgery by two surgical teams. At 2 weeks, all patients were independent in mobility. There was no difference in pivot shift, Lysholm and Tegner scores at 1 year when compared to published outcomes for unilateral ACL reconstruction. The median duration of follow-up was 28 months (range 12–50 months). Based on these small numbers, our results demonstrate that simultaneous bilateral ACL reconstruction is a safe and clinically effective option when using either hamstring or patella tendon graft.     

MRI analysis of tibial position of the anterior cruciate ligament

This study aimed to establish normal values for the position of the native anterior cruciate ligament (ACL) insertion on the tibia to assist in the evaluation of tunnel placement after primary ACL reconstruction or prior to revision surgery. One hundred consecutive MRI studies performed on patients with a mean age of 29 years (range 20–35) from a single MRI facility were reviewed. Patients with prior surgery, significant osteoarthritis, acute ACL injury, or evidence of ACL reconstruction were excluded. Using digital image software, measurements were taken of anterior-most and posterior-most portions of the ACL insertion on the tibia. Depth of the tibia was also measured from the anterior edge of the tibial plateau to the posterior edge at the origin of the posterior cruciate ligament. The anterior insertion of the native ACL was located at a mean of 14 ± 3 mm (28 ± 5%) from the anterior tibial articular margin; the posterior portion of the ACL was located at a mean of 31 ± 4 mm (63 ± 6%). The tibial insertion of the ACL is located between 28 and 63% of the total anterior–posterior depth of the tibia. The results from this study are clinically relevant as they provide the clinician with baseline data to describe the position of the tibial footprint of the native ACL on sagittal MR imaging. Further, this data can be used as a guide to evaluate tibial tunnel position prior to primary ACL reconstruction, revision ACL surgery, or in ACL-reconstructed patients who continue to experience pain, instability, or dysfunction postoperatively.     

ACL deficiency affects stride-to-stride variability as measured using nonlinear methodology

Previous studies suggested that the small fluctuations present in movement patterns from one stride to the next during walking can be useful in the investigation of various pathological conditions. Previous studies using nonlinear measures have resulted in the development of the “loss of complexity hypothesis” which states that disease can affect the variability and decrease the complexity of a system, rendering it less able to adjust to the ever changing environmental demands. The nonlinear measure of the Lyapunov Exponent (LyE) has already been used for the assessment of stride-to-stride variability in the anterior cruciate ligament (ACL) deficient knee in comparison to the contralateral intact knee. However, there is biomechanical evidence that after ACL rupture, adaptations are also present in the contralateral intact knee. Thus, our goal was to investigate stride-to-stride variability in the ACL deficient knee as compared to a healthy control knee. Seven subjects with unilateral ACL deficiency and seven healthy controls walked at their self-selected speed on a treadmill, while three-dimensional knee kinematics was collected for 80 consecutive strides. A nonlinear measure, the largest LyE was calculated from the resulted knee joint flexion-extension data of both groups. Larger LyE values signify increased variability and increased sensitivity to initial conditions. Our results showed that the ACL deficient group exhibited significantly less variable walking patterns than the healthy control. These changes are not desirable because they reflect decreases in system’s complexity, which indicates narrowed functional responsiveness, according to the “loss of complexity hypothesis.” This may be related with the increased future pathology found in ACL deficient patients. The methods used in the present paper showed great promise to assess the gait handicap in knee injured patients.     

Surgical management of partial tears of the anterior cruciate ligament

Purpose

Partial anterior cruciate ligament (ACL) tears involving the posterolateral (PL) bundle can lead to rotatory laxity of the knee, while tears involving the anteromedial (AM) bundle result in abnormal anteroposterior laxity of the knee. In this systematic review, we examine the best evidence on the management of partial tears of the ACL.

Methods

A comprehensive search of several databases was performed from the inception of the database to December 2011, using various combinations of keywords focusing on clinical outcomes of human patients who had partial tears of ACL and who had undergone ACL augmentation. We evaluated the methodological quality of each article using the Coleman Methodology Score.

Results

Ten articles published in peer-reviewed journals were identified (392 males and 242 females), with a mean modified Coleman methodology of 66.1 ± 10.2. Only two studies compared standard ACL reconstruction and augmentation techniques. No study has a sample large enough to allow establishing guidelines. Validated and standardized proprioception assessment methods should be used to report outcomes. Imaging outcomes should be compared to functional outcomes, and a control group consisting of traditional complete ACL reconstruction should be present.

Conclusion

There is a need to perform appropriately powered randomized controlled trials presenting clinical outcome with homogeneous score systems to allow accurate statistical analysis. ACL augmentation technique, preserving the intact AM or PL bundle of the ACL, is encouraging but currently available evidences are too weak to support his routine use in clinical practice.

Level of evidence

Systematic review, Level IV.     

Blood flow measurement in reconstructed anterior cruciate ligaments using laser Doppler flowmetry

Laser Doppler flowmetry (LDF) was used to measure blood flow in anterior cruciate ligaments (ACL) reconstructed using a bone-patellar tendon-bone autograft. Thirty-five patients (17 men, 18 women) undergoing second-look arthroscopy for a reconstructed ACL were selected at random for postoperative participation in the study at 6, 12, and 18 months. Eight patients with an intact ACL had their blood flow measured arthroscopically for a control. Under arthroscopic visualization, a 3 mm probe was placed through a trocar sleeve into the ACL. Functional flow was evaluated using LDF, for which the output signal, the blood cell flux (BCF), is expressed in terms of volts. These patients also underwent magnetic resonance imaging (MRI); MRI, IKDC final evaluation, and second-look arthroscopic findings for each patient were compared with the others. In normal ACL, the BCF value ranged from 120 to 130 mV, and synovial blood flow, 90–132 mV. Significantly high BCF values for the reconstructed ACL were noted at 6 and 12 months, but there was no change in synovial BCF postoperatively. There was a gradual return to near normal BCF values for the reconstructed ACL 18 months after surgery. Significantly abnormal BCF values (580 ± 20 mV) were seen in cases with a severely abnormal IKDC final evaluation; there were few differences in BCF values between normal, nearly normal, and abnormal. LDF is easy to use and appears to be a reproducible technique for evaluating blood flow in the reconstructed ACL, offering distinct advantages for evaluating its maturation. Six months after surgery, there was a decrease in MRI with a high signal intensity, whereas the BCF values in the reconstructed ACL generally needed 18 months to return to near normal; the return was gradual. We believe the blood supply of the reconstructed ACL may originate from the synovium of posterior joint capsule within 6 months after surgery. Received: 17 February 1997 Accepted: 13 October 1997     

Bucket handle tears of the medial meniscus: meniscal intrusion rather than meniscal extrusion

Objective To determine the frequency of medial meniscal extrusion (MME) versus “medial meniscal intrusion” in the setting of bucket handle tears. Images were evaluated for previously reported risk factors for MME, including: medial meniscal root tear, radial tear, degenerative joint disease and joint effusion. Methods Forty-one consecutive cases of bucket handle tear of the medial meniscus were reviewed by consensus by two musculoskeletal radiologists. Imaging was performed using a 1.5 GE Signa MR unit. Patient age, gender, medial meniscal root integrity, MME, medial meniscal intrusion, degenerative joint disease, effusion and anterior cruciate ligament (ACL) tear were recorded. Results Thirteen females and 27 males (age 12–62 years, median=30 years) were affected; one had bucket handle tear of each knee. Effusion was small in 13, moderate in 9 and large in 18. Degenerative joint disease was mild in three, moderate in two and severe in one. 26 ACL tears included three partial and three chronic. Medial meniscal root tear was complete in one case and partial thickness in two. None of the 40 cases with an intact or partially torn medial meniscal root demonstrated MME. MME of 3.1 mm was seen in the only full-thickness medial meniscal root tear, along with chronic ACL tear, moderate degenerative joint disease and large effusion. Medial meniscal intrusion of the central bucket handle fragment into the intercondylar notch was present in all 41 cases. Conclusion Given an intact medial meniscal root in the setting of a “pure” bucket handle tear, there is no MME.     

A long-term study of anterior cruciate ligament allograft reconstruction

We retrospectively reviewed the long-term clinical outcome of unilateral arthroscopic anterior cruciate ligament (ACL) allograft reconstruction. From October 1995 to December 1997, 64 arthroscopic ACL reconstructions were performed. Multiligamentous knee injuries and ACL injuries in polytrauma patients were excluded and out of the remaining 60 patients 55 were available for follow-up. Three patients had suffered a rerupture caused by major trauma. One patient had a rerupture without significant trauma and one failure was caused by deep infection. These five patients were revised. Fifty patients (36 males, 14 females) were included in the final follow-up. At the time of evaluation, the mean duration of follow-up was 10 years and 6 months. All patients were examined by an independent examiner. Seven patients had an extension lag (<5°) and all patients had a knee flexion of at least 120°, with a mean flexion of 135 ± 5° compared to 135 ± 8°. At the time of follow-up, the median IKDC score was 97 (74–100). The Lysholm scoring scale had a median value of 95 (76–100). The median sports level on the Tegner scale was 6 (4–9). The one-leg-hop test showed a mean value of 95 ± 5%. One patient did not perform the one-leg-hop test because of recent surgery to the Achilles tendon. In conclusion, the tibialis anterior or tibialis posterior tendon allograft ACL reconstruction produced good clinical results in the majority of patients at long-term follow-up.     

The resident’s ridge as an arthroscopic landmark for anatomical femoral tunnel drilling in ACL reconstruction

The purposes of this study were to establish the technique to arthroscopically identify the resident’s ridge without bony notchplasty even in patients with chronic ACL insufficiency and to elucidate if the ridge could be used as a landmark for anatomical femoral tunnel for ACL graft. There were 50 consecutive patients undergoing arthroscopic ACL reconstruction. With the thigh kept horizontal using a leg holder, a meticulous effort was made to find out a linear ridge running proximo-distal in a posterior one-third of the lateral notch wall, after removal of superficial soft tissue with radiofrequency energy. If the ridge was found, a socket with a rectangular aperture of 5 × 10 mm was created just behind the ridge. At 3–4-weeks post surgery, three-dimensional computed tomography (3-D CT) was performed to geographically identify the location of the ridge using the socket as a reference. Arthroscopically, a linear ridge running from superior-anterior to inferior-posterior on the lateral notch wall was consistently observed 7–10 mm anterior to the posterior articular cartilage margin of the lateral femoral condyle in all of the patients. The 3-D CT pictures proved the arthroscopically identified ridge to be the resident’s ridge. The resident’s ridge is arthroscopically identifiable after non-mechanical removal of the soft tissues without bony notchplasty. The ridge is a useful landmark for anatomical femoral tunnel drilling in arthroscopic ACL reconstruction.