Anterior cruciate ligament reconstruction. The effect of tibial tunnel placement on range of motion

Arthrofibrosis of the knee in pediatric orthopedic surgery

Arthrofibrosis is a challenging complication associated with knee injuries in both children and adults. While much is known about managing arthrofibrosis in adults, it is necessary to understand its unique aspects and management strategies in the pediatric population. This paper provides an overview of arthrofibrosis in pediatric orthopedic surgery, focusing on its causes, implications, classifications, and management. This paper is a comprehensive review of the literature and existing research on arthrofibrosis in pediatric patients. Arthrofibrosis is characterized by excessive collagen production and adhesions, leading to restricted joint motion and pain. It is associated with an immune response and fibrosis within and around the joint. Arthrofibrosis can result from various knee injuries in pediatric patients, including tibial spine fractures, ACL and PCL injuries, and extra-articular procedures. Technical factors at the time of surgery play a role in the development of motion loss and should be addressed to minimize complications. Preventing arthrofibrosis through early physical therapy is recommended. Non-operative management, including dynamic splinting and serial casting, has shown some benefits. New pharmacologic approaches to lysis of adhesions have shown promise. Surgical interventions, consisting of arthroscopic lysis of adhesions (LOA) and manipulation under anesthesia (MUA), can significantly improve motion and functional outcomes. Arthrofibrosis poses unique challenges in pediatric patients, demanding a nuanced approach that includes prevention, early intervention with non-operative means, and improvements in surgical techniques. Modern pharmacological interventions offer promise for the future. Customized interventions and research focused on pediatric patients are critical for optimal outcomes.

Localized Anterior Arthrofibrosis After Soft-Tissue Quadriceps Tendon Anterior Cruciate Ligament Reconstruction Is More Common in Patients Who Are Female, Undergo Meniscal Repair, and Have Grafts of Larger Diameter

PURPOSE

To determine factors associated with localized anterior arthrofibrosis (cyclops lesion), such as graft size, warranting early reoperation for lysis of adhesions after anterior cruciate ligament reconstruction (ACLR) with all-soft tissue quadriceps tendon (ASTQT) autograft.

METHODS

All primary ASTQT autograft ACLRs within a single surgeon's prospectively collected registry with minimum 6-month follow-up were included. Patients who underwent multiligament knee reconstruction or cartilage restoration procedures were excluded. Localized anterior arthrofibrosis was defined as the requirement for a second procedure to achieve debridement and lysis of adhesions owing to the inability to regain terminal extension within 6 months of ACLR. The sex-specific incidence of arthrofibrosis was evaluated relative to age, weight, femoral and tibial tunnel sizes, meniscal repair, and meniscectomy by a binary logistic regression.

RESULTS

This study included 721 patients (46% female patients). There were 52 cases of localized anterior arthrofibrosis (7.2%). Female patients had a greater incidence of arthrofibrosis than male patients. Male patients with a femoral tunnel diameter of 9.25 mm or greater had an increased incidence of arthrofibrosis compared with those with a diameter of less than 9.25 mm, whereas a similar cutoff was not found to be statistically significant for female patients. Concomitant meniscal repair was associated with an increased risk of arthrofibrosis.

CONCLUSIONS

Female sex and concomitant meniscal repair were associated with an increased localized anterior arthrofibrosis incidence. Furthermore, ASTQT with a femoral tunnel diameter of 9.25 mm or greater in male patients was associated with an increased incidence of arthrofibrosis. LEVEL OF EVIDENCE: Level III, retrospective, comparative prognostic trial.

Clinical Management of Arthrofibrosis: State of the Art and Therapeutic Outlook

* Arthrofibrosis is a pathologic condition that is characterized by excessive periarticular scar-tissue formation. Arthrofibrosis may occur secondary to injury, surgical trauma, hemarthrosis, or infection, or it may occur idiopathically.* The pathogenesis of arthrofibrosis is incompletely understood but involves the dysregulation of normal reparative pathways, with transforming growth factor-beta (TGF-[beta]) as a principal mediator.* Current treatment options for arthrofibrosis primarily involve physiotherapy, operative manipulation, and surgical debridement, all with imperfect results.* Currently, there are no pharmacologic treatment options for arthrofibrosis. This has prompted increased investigational interest in the development of antifibrotic intra-articular therapies.

Arthrogenic muscle inhibition and return to sport after arthrofibrosis complicating anterior cruciate ligament surgery

Arthrofibrosis is a devastating complication after Anterior Cruciate Ligament reconstruction (ACLr) characterized by a muscle weakness secondary to an arthrogenic muscle inhibition process. The loss of knee isokinetic strength due to arthrogenic muscle inhibition may be more important after arthrofibrosis, compared to an ACLr population with no complication. The isokinetic strength deficit [Limb Symmetry Index (LSI) at 60 and 180°/s of angular speed] was measured at 4, 7 and 12 post-operative months. Knee function, return to running and return to sport were evaluated. A comparison of the Quadriceps and the Hamstring LSI between patients with arthrofibrosis and those without post-operative complication was performed according to time and taking into consideration the type of surgical procedure. 539 primary ACLr patients were assessed. The arthrofibrosis group presented at 4, 7 and 12 post-operative months a Quadriceps LSI significantly lower compared to the control group, without influence of the graft procedure (LSI: 38, 53, 68% vs 63, 73, 85% at 60°/s, respectively). The Hamstring LSI was significantly lower at 4 and 7 post-operative months, but comparable at 12 months with an influence of the Hamstring procedure. Knee function was significantly lower at 4 and 7 post-operative months. Few arthrofibrosis ACLr patients returned to running at 7 post-operative months (6.8% vs 69.9%; p < .0001). An important and durable Quadriceps muscle weakness occurred after arthrofibrosis, whatever the type of graft procedure. This is explained by an Arthrogenic muscle inhibition which compromised the return to sport at the same level until 12 post-operative months. HighlightsAn important and durable quadriceps muscle weakness occurred after arthrofibrosis.The arthrogenic muscle inhibition was significant on the operated side independently of the type of the graft procedure.Arthrogenic muscle inhibition compromised the return to sport at the same level until 12 post-operative months.

Association of the Graft Size and Arthrofibrosis in Young Patients After Primary Anterior Cruciate Ligament Reconstruction

INTRODUCTION

This study investigated the association of graft-related surgical factors and patient characteristics with the odds of arthrofibrosis after primary anterior cruciate ligament reconstruction (ACL-R).

METHODS

A retrospective case-control study assessed consecutive patients who underwent primary ACL-R in one tertiary pediatric hospital. Each arthrofibrosis case was matched to three controls for sex, calendar year, and age at the time of ACL-R, as well as the primary surgeon. Conditional multivariable logistic regression assessed the independent association of graft diameter, time from injury to ACL-R, concomitant knee pathologies, and body mass index.

RESULTS

Twenty arthrofibrosis cases of 1,121 ACL-R patients (incidence 1.8%) were matched to 60 controls resulting in the mean age of 14.5 years. An increase of 1 mm graft diameter was associated with 3.2-times increased odds of arthrofibrosis. Other variables were not independently associated with arthrofibrosis.

CONCLUSION

For young patients, the decision on the graft size must consider the possibility of arthrofibrosis with a larger graft versus reinjury with a smaller graft.

Clinical Outcomes After Arthroscopic Release of Patellofemoral Arthrofibrosis in Patients With Prior Anterior Cruciate Ligament Reconstruction

PURPOSE

The purpose of this study was to review our results of arthroscopic release in patients diagnosed with refractory patellofemoral arthrofibrosis (PFA) after having undergone anterior cruciate ligament (ACL) reconstruction.

METHODS

From 2006 to 2016, all patients who underwent arthroscopic release for refractory PFA after ACL reconstruction were reviewed retrospectively. All patients then completed surveys containing the International Knee Documentation Committee (IKDC) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and were asked 2 subjective questions. Patients included in the study exhibited at least one finding of PFA and failed conservative treatment for at least 3 months. Included patients also had a minimum of 12 months of postoperative follow-up after PFA release. Patients who underwent any other concomitant surgery in the same operative setting as arthroscopic release for PFA were excluded from the study.

RESULTS

Thirty-two patients were included in the study. The mean age was 32.8 years (range, 19-58 years) with an average follow-up of 43.6 months (range, 16-98 months). There was a statistically significant increase preoperatively to postoperatively in the IKDC score from 49.6 to 69.4 (P < .00001), and 16 of 32 patients (50%) achieved a minimal clinically important difference (MCID). WOMAC scores also significantly increased from 74 to 85.3 (P < .00001), with 15 of 32 patients (47%) achieving MCID. Thirty-one patients (97%) reported that the procedure helped, and 25 patients (78%) said they would have the procedure again.

CONCLUSIONS

Arthroscopic release, consisting of an extended lateral release, debridement of the notch/fat pad, and manual manipulation of the patella, results in significant increases in validated outcome measures and is well tolerated by patients.

LEVEL OF EVIDENCE

Level IV, case series.

Anterior cruciate ligament reconstruction tunnel size: causes of tunnel enlargement and implications for single versus two-stage revision reconstruction

Anterior cruciate ligament (ACL) reconstructions have increased over the past 25 years. The increased incidence of ACL reconstructions has translated into a larger number of graft failures and revision ACL procedures. It is important to understand the causes of graft failure when evaluating for a revision ACL reconstruction and to appreciate changes in tunnel anatomy over time prior to planning revision surgery. In this manuscript, tunnel size for ACL reconstruction and implications for single-stage versus two-stage revision ACL reconstruction will be discussed, as well as causes of tunnel enlargement, including mechanical and biological factors.

The influence of graft placement on clinical outcome in anterior cruciate ligament reconstruction

PURPOSE

the aim of the present study was to investigate the influence of graft tunnel position on both clinical outcome and instrumental knee stability in patients submitted to arthroscopic ACL reconstruction using a bone-patellar tendon-bone (BPTB) graft.

METHODS

thirty patients (24 men and 6 women) who underwent ACL reconstruction performed using an autologous bone-patellar tendon-bone graft were studied at a mean follow-up of 18 months. Clinical outcome was assessed on the basis of the Lysholm score, Tegner activity level, International Knee Documentation Committee (IKDC) subjective form and the Short Form-36. Clinical outcomes were correlated with both femoral and tibial tunnel placement measured on standard anteroposterior and lateral knee radiographs, in accordance with established guidelines.

RESULTS

tibial tunnel position on the lateral view correlated significantly with both the IKDC subjective form (r = -0.72; p<0.05) and the Lysholm score (r=-0.73; p<0.05). Tibial tunnel position on the lateral view also correlated with stability measured using a KT-1000 arthrometer at 30N of force (r=0.57; p<0.05). No correlation was found between α angle and anteroposterior (AP) laxity measured by KT-1000 arthrometer. No significant correlation was found between femoral tunnel position (on either view) and Lysholm score, IKDC score and Tegner activity level. Similarly, no correlation was found between AP laxity measured by KT-1000 arthrometer and femoral tunnel position.

CONCLUSIONS

these results suggest that the more anterior the placement of the tibial tunnel, the better the clinical outcome will be. On the basis of literature data and our findings, we discuss the hypothesis that there exists a "correct area" for tunnel placement, making it possible to obtain the best results.

LEVEL OF EVIDENCE

Level IV, case series.

Evaluation and Comparison of Femoral Tunnel Placement During Anterior Cruciate Ligament Reconstruction Using 3-Dimensional Computed Tomography: Effect of Notchplasty on Transtibial and Medial Portal Drilling

BACKGROUND

Advocates of medial portal drilling claim that the transtibial technique results in a more vertical positioning of the graft, which could lead to subsequent failure and/or a residual pivot shift on postoperative examination. However, advocates of transtibial drilling state that with appropriate placement and adequate notchplasty, their technique places the graft in a more anatomically correct position on the wall, negating the resultant potential for pivot shift and early postoperative failure.

HYPOTHESIS

Transtibial femoral drilling can adequately reproduce the femoral origin of the anterior cruciate ligament (ACL) and place the graft in an anatomical position equivalent to medial portal drilling.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten matched-pair cadaveric knees (N = 20) were scanned using computed tomography (CT), and 3-dimensional images of the native ACL origin were reconstructed. The matched pairs were then randomized into transtibial and medial portal groups. The femoral tunnel was drilled in each knee according to group. A bamboo skewer was placed in the femoral tunnel, and the knees underwent a second CT scan. Arthroscopic notchplasty was performed, and the femoral tunnels were redrilled. Radiographs confirmed placement, and the post-notchplasty tunnel was reamed with a 4-mm reamer. The knees underwent a third CT scan. CT scans compared femoral tunnel placement with the native ACL footprint before and after notchplasty.

RESULTS

The post-notchplasty transtibial group revealed an average of 68.3% coverage of the native ACL femoral origin. The medial portal group revealed an average of 60.8% coverage, with 1 instance of perforation of the posterior cortex. There were no instances of perforation in the transtibial group.

CONCLUSION

Both drilling techniques place the graft in an anatomically correct position.

CLINICAL RELEVANCE

Transtibial drilling of the femur can adequately place the entry tunnel at the origin of the ACL's native footprint.

Applications of computer navigation in sports medicine knee surgery: an evidence-based review

Computer-assisted surgery (CAS) has been investigated in a number of sports medicine procedures in the knee. Current barriers to its widespread introduction include increased costs, duration, and invasiveness of surgery. Randomized trials on the use of CAS in anterior cruciate ligament reconstruction have failed to demonstrate a clinical benefit. Data on CAS use in high tibial osteotomy are more promising; however, long-term studies are lacking. CAS has a number of research applications in knee ligament surgery, and studies continue to explore its use in the treatment of osteochondral lesions. This article reviews the applications of CAS in sports medicine knee surgery and summarizes current literature on clinical outcomes.

Long-term results of anterior cruciate ligament reconstruction using bone-patellar tendon-bone: an analysis of the factors affecting the development of osteoarthritis

PURPOSE

To evaluate the clinical outcomes and incidence of knee osteoarthritis (OA) and the factors associated with the onset of OA in the 3 compartments of the knee joint separately after anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone autograft.

METHODS

Clinical and radiologic assessments were obtained from 117 patients (80.1%). At follow-up, knee function was evaluated with the Lysholm score, Hospital for Special Surgery (HSS) score, Tegner score, and International Knee Documentation Committee (IKDC) 2000 forms. We also evaluated stability and donor-site morbidity. On the follow-up radiographs, OA was assessed by IKDC grading. The factors affecting the onset of OA in the 3 compartments of the knee joint were evaluated.

RESULTS

The mean follow-up period was 10.3 ± 1.0 years. The mean Lysholm and HSS scores significantly increased at final follow-up (P < .001). The mean IKDC subjective score was 90.6, and 93.9% of patients had grade A or grade B knees on the objective evaluation. The mean side-to-side difference measured by KT-2000 arthrometer (MEDmetric, San Diego, CA) was 1.6 ± 1.7 mm, with 82.0% of patients showing a difference of less than 3 mm. Discomfort from knee walking on hard ground and skin numbness were reported by 38.4% and 37.6% of patients, respectively. OA developed in the medial, lateral, and patellofemoral compartments in 30.7%, 9.3%, and 7.6% of patients, respectively. The onset of OA was associated with partial meniscectomy (odds ratio [OR], 20.73; P = .005) or sagittal tibial tunnel position (OR, 1.18; P = .02) in the medial compartment and body mass index (BMI) (OR, 1.56; P = .02) in the lateral compartment.

CONCLUSIONS

ACL reconstruction with bone-patellar tendon-bone autograft showed satisfactory clinical results after a mean of 10.3 years. However, pain when walking on hard ground (38.4%) and numbness of the skin (37.6%) were reported. Moreover, the onset of OA appeared in over 40% of the patients. The onset of OA in the medial compartment was correlated with partial meniscectomy and sagittal tibial tunnel position, and the onset of OA in the lateral compartment was correlated with higher BMI.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Does computer navigation system really improve early clinical outcomes after anterior cruciate ligament reconstruction? A meta-analysis and systematic review of randomized controlled trials

Inaccurate tunnel placement is an important cause of failure in conventional anterior cruciate ligament (ACL) reconstruction. Controversy currently exists over the usefulness of computer-assisted navigation systems in addressing this problem. Five randomized or quasi-randomized, controlled trials comparing computer-navigated versus conventional technique in ACL reconstructions until December 1, 2009 were identified through a systematical database search. The clinical outcomes of the trials were analyzed by Lachman test, pivot-shift test, International Knee Documentation Committee knee score, Lysholm score, and Tegner score. Mean difference or risk ratio with 95% confidence interval was calculated using a fixed-effects or random-effects model. Heterogeneity across the studies was also assessed. We found that the use of computer-assisted navigation systems led to additional operative time (8-17min). No significant differences between computer-navigated and conventional groups were found in terms of knee stability and functional assessment during short-term follow-up. The role of computer-assisted navigation systems on clinical performance and longevity needs further investigation in large sample, long-term randomized trials.

Reliability of tunnel angle in ACL reconstruction: two-dimensional versus three-dimensional guide technique

PURPOSE

To compare the reliability of tibial tunnel position and angle produced with a standard ACL guide (two-dimensional guide) or Howell 65° Guide (three-dimensional guide) in the coronal and sagittal planes. In the sagittal plane, the dependent variables were the angle of the tibial tunnel relative to the tibial plateau and the position of the tibial tunnel with respect to the most posterior aspect of the tibia. In the coronal plane, the dependent variables were the angle of the tunnel with respect to the medial joint line of the tibia and the medial and lateral placement of the tibial tunnel relative to the most medial aspect of the tibia.

METHODS

The position and angle of the tibial tunnel in the coronal and sagittal planes were determined from anteroposterior and lateral radiographs, respectively, taken 2-6 months postoperatively. The two-dimensional and three-dimensional guide groups included 28 and 24 sets of radiographs, respectively. Tibial tunnel position was identified, and tunnel angle measurements were completed. Multiple investigators measured the position and angle of the tunnel 3 times, at least 7 days apart.

RESULTS

The angle of the tibial tunnel in the coronal plane using a two-dimensional guide (61.3 ± 4.8°) was more horizontal (P < 0.05) than tunnels drilled with a three-dimensional guide (64.7 ± 6.2°). The position of the tibial tunnel in the sagittal plane was more anterior (P < 0.05) in the two-dimensional (41.6 ± 2.5%) guide group compared to the three-dimensional guide group (43.3 ± 2.9%).

CONCLUSION

The Howell Tibial Guide allows for reliable placement of the tibial tunnel in the coronal plane at an angle of 65°. Tibial tunnels were within the anatomical footprint of the ACL with either technique. Future studies should investigate the effects of tibial tunnel angle on knee function and patient quality of life.

LEVEL OF EVIDENCE

Case-control retrospective comparative study, Level III.

Causes for failure of ACL reconstruction and influence of meniscectomies after revision

The purpose of this multicenter retrospective study was to analyze the causes for failure of ACL reconstruction and the influence of meniscectomies after revision. This study was conducted over a 12-year period, from 1994 to 2005 with ten French orthopaedic centers participating. Assessment included the objective International Knee Documenting Committee (IKDC) 2000 scoring system evaluation. Two hundred and ninety-three patients were available for statistics. Untreated laxity, femoral and tibial tunnel malposition, impingement, failure of fixation were assessed, new traumatism and infection were recorded. Meniscus surgery was evaluated before, during or after primary ACL reconstruction, and then during or after revision ACL surgery. The main cause for failure of ACL reconstruction was femoral tunnel malposition in 36% of the cases. Forty-four percent of the patients with an anterior femoral tunnel as a cause for failure of the primary surgery were IKDC A after revision versus 24% if the cause of failure was not the femoral tunnel (P = 0.05). A 70% meniscectomy rate was found in revision ACL reconstruction. Comparison between patients with a total meniscectomy (n = 56) and patients with preserved menisci (n = 65) revealed a better functional result and knee stability in the non-meniscectomized group (P = 0.04). This study shows that the anterior femoral tunnel malposition is the main cause for failure in ACL reconstruction. This reason for failure should be considered as a predictive factor of good result of revision ACL reconstruction. Total meniscectomy jeopardizes functional result and knee stability at follow-up.

Tunnel positioning in anterior cruciate ligament reconstruction: how long is the learning curve?

The purpose of this study is to investigate the effect of the learning curve on radiographic tunnel position. A consecutive series of the first 200 procedures of an orthopaedic surgeon over his initial 4years of independent practice were analysed for tunnel placement, based on radiographic appearance. An arthroscopic-assisted technique using patella tendon as graft material was performed in all cases. To establish femoral tunnels, a transtibial guide pin was used. The graft was secured with bioabsorbable screws. A Frik tunnel view and a strictly lateral radiograph were used to assess tunnel placements. Tunnel positioning was assessed using a computer-aided design, 2D software (Auto CAD2000(®)). To minimize measurement bias, radiographs were assessed three times or until deviations in all three measurements were less than 10%, and the three measurements were then averaged. Sagittal femoral tunnel placement improved significantly (P = 0.01) after the first 100 cases. Significant improvement (P = 0.05) in coronal femoral tunnel placement was observed after the first 75 cases. Significant improvement (P = 0.01) in sagittal tibial tunnel position was observed after the first 100 cases. Mean coronal tibial tunnel did not improve. Critical analysis in this consecutive series suggests that a caseload of approximately 100 procedures were necessary for this surgeon to refine his surgical technique beyond that acquired during formal training.

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.

What is the role of intra-operative fluoroscopic measurements to determine tibial tunnel placement in anatomical anterior cruciate ligament reconstruction?

The hypothesis for this study was that intra-operative fluoroscopic measurements can be used to determine tibial tunnel placement during anatomic anterior cruciate ligament (ACL) reconstruction. The anteromedial (AM) and posterolateral (PL) bundle insertion sites were marked with a thermal device and measured in a consecutive cohort of 67 patients undergoing anatomical ACL reconstruction. For double bundle reconstruction, guide pins were passed in the center of the AM and PL tibial footprints. For single bundle (SB) reconstruction a guide wire was placed between the center of AM and PL footprints. Subsequently, the position of the centers of the AM and PL insertion sites were measured on standardized lateral intra-operative fluoroscopic images. The center for the AM bundle was found to be at 31% (range 20-42%) of the AP distance on the medial joint line and at 35% (range 23-42%) of the AP distance on the Amis and Jakob line. The center of the PL bundle was at 48% (range 37-59%) of the AP distance on the medial joint line and 48% (range 39-58%) of the AP distance on the Amis and Jakob line. The center of the tibial tunnel in the SB group (n = 15) was at 42 and 41% in relation to the medial joint line and the Amis and Jakob line, respectively. Because a significant anatomic variation exists between patients, the decision with respect to tunnel placement should not be merely based on intra-operative fluoroscopic images.

Development and in situ application of an adjustable aiming device to guide extra- to intraarticular tibial tunnel drilling for the insertion of the cranial cruciate ligament in dogs

OBJECTIVE

To develop and test an arthroscopic aiming device for extra- to intraarticular tibial tunnel drilling emerging at the center of the tibial insertion (CenterTib) of the cranial cruciate ligament (CCL) in medium to large breed dogs.

STUDY DESIGN

Descriptive experimental study.

SAMPLE POPULATION

Fifty-two cadaveric hind limbs of dogs >or=20 kg BW.

METHODS

The mediolateral position and craniocaudal position (ccPos) of CenterTib in relation to the caudomedial meniscotibial ligament were measured on photographs of 46 dissected tibial plateaus. The proximal tibial depth (TibDepth) was determined on lateral radiographs and its correlation with ccPos was assessed using linear regression analysis. Extra- to intraarticular arthroscopic tibial tunnel drilling was performed in 6 independent cadaveric stifles. A C-guide with an adjustable craniocaudal offset was constructed and adjusted according to ccPos estimated based on TibDepth. The position of the resulting bone tunnels was compared with the position of the CenterTib.

RESULTS

Pearson's correlation between TibDepth and ccPos was strong (R=0.86; P<.001). ccPos (y) as a function of TibDepth (x) can be expressed as y=-4.8+0.3x. Arthroscopic tunnel drilling resulted in a median deviation of the drill tunnels around the CenterTib of 1 mm.

CONCLUSION

The regression equation and aiming device permit localization and targeting of CenterTib during extra- to intraarticular tibial bone tunnel drilling in vitro.

CLINICAL RELEVANCE

The proposed technique may reduce tibial tunnel misplacement when performing intraarticular CCL repair using a tibial bone tunnel.

Anteromedial portal versus transtibial drilling techniques in ACL reconstruction: a blinded cross-sectional study at two- to five-year follow-up

Drilling of the femoral tunnel with the transtibial (TT) technique is widely used in bone-patellar tendon-bone (BPTB) anterior cruciate ligament (ACL) reconstruction. Recent studies suggest higher knee stability with the use of the anteromedial portal (AMP). The purpose of this study was to compare functional and clinical outcomes of BPTB ACL reconstruction using the TT or the AMP technique for drilling the femoral tunnel. All ACL reconstructions between January 2003 and April 2006 were approached for eligibility. Forty-seven patients met inclusion criteria (21 TT group and 26 AMP group). Blinded assessments of IKDC score, knee stability and range of motion, one-leg hop test, mid-quadriceps circumference, VAS for satisfaction with surgery, Lysholm and Tegner scores, and SF-12 questionnaire were obtained for both groups. Data on preoperative and postoperative surgical timing were retrospectively reviewed through the charts. The AMP group demonstrated a significantly lower recovery time from surgery to walking without crutches (p < 0.01), to return to normal life (p < 0.03), to return jogging (p < 0.03), to return training (p < 0.03), and to return to play (p < 0.03). Knee stability values measured with KT-1000, Lachman test, pivot-shift sign, and objective IKDC score assessments were significantly better for the AMP compared to TT group (p < 0.002, p < 0.03, p < 0.02, p < 0.015, respectively). No differences were found for VAS for satisfaction with surgery, Lysholm, Tegner, and SF-12 between both groups. The use of the AMP technique significantly improved the anterior-posterior and rotational knee stability, IKDC scores, and recovery time from surgery compared to the TT technique.

Influence of the bone block position on the tunnel enlargement in ACL reconstruction

Tunnel enlargement can appear after anterior cruciate ligament reconstruction. We investigated the influence of the bone block position of a patellar tendon autograft on the tunnel enlargement in the femur and in the tibia from two aspects. On the one hand, we examined the influence of the tunnel position in respect to the ap-diameter. On the other hand, we examined the influence of the bone block depth in respect to the joint line. In a crossover study over three years, 103 knees with primary ACL reconstruction were included. The incidence of tunnel enlargement measured on X-rays after one year was 52% (n=103) in the femur and 81% (n=103) in the tibia. The average diameter of enlargement was 1.4 mm (14%) in the femur and 2.7 mm (27%) in the tibia. No correlation between the tunnel position and the tunnel enlargement in the sagital plane could be found. However, there is a significant positive correlation between the size of tunnel enlargement and the bone block depth in the femur and in the tibia. There is an average tunnel enlargement of about 0.6 mm (6%) per 10 mm deeper bone plug depth. The relative excess length of the patella tendon favors the development of tunnel enlargement. The effect of the bone block depth on the tunnel enlargement is equal in the femur and the tibia.

Anterior cruciate ligament reconstruction with and without computer navigation: a clinical and magnetic resonance imaging evaluation 2 years after surgery

PURPOSE

The purpose of this study was to evaluate the benefits of computer navigation on tunnel placement during anterior cruciate ligament reconstruction.

METHODS

A prospective, randomized, controlled study comparing computer navigation with manual operation was performed between December 2003 and April 2004. We assigned 20 patients to the computer navigation group and 20 patients to the manual navigation group. Surgery was performed by use of a patellar tendon autograft with press-fit fixation. A lateral radiograph of the knee at maximum extension was used to determine the exact position of the tibial tunnel at 4 days postoperatively. Outcomes were evaluated with International Knee Documentation Committee 2000, Tegner, and Lysholm scoring. There was an additional magnetic resonance imaging (MRI) evaluation of tunnel placement and graft quality at the most recent follow-up, approximately 24 months after surgery.

RESULTS

The postoperative radiographs and 2-year postoperative MRI scans showed no differences between groups for tibial or femoral tunnel placement. In both groups the mean tibial tunnel placement was 46% of the maximal diameter of the tibia. There were no significant differences between groups for objective and subjective outcomes scoring. Although some qualitative differences existed between groups with respect to MRI graft appearance at 2 years, this had no correlation with overall results.

CONCLUSIONS

No significant differences were found between computer-assisted and manually navigated anterior cruciate ligament reconstruction with regard to tunnel placement and clinical results at a mean of 2 years postoperatively.

LEVEL OF EVIDENCE

Level I, randomized, single-blinded, controlled trial.

Tunnel enlargement after anterior cruciate ligament reconstruction in patients with post-operative septic arthritis

Tunnel enlargement is a frequent issue after ACL reconstruction and the "synovial bathing effect" is thought to be among the biological factors contributing to this phenomenon. Since the amount and the pressure of the synovial fluid inside the knee joint are higher and the length of its presence is longer in patients with post-operative septic arthritis after ACL reconstruction, we reviewed the tunnel enlargement in these cases in order to better evaluate this phenomenon in such a hostile environment. The null hypothesis of this study was that the highly represented phenomenon of the "synovial bathing effect" that occurs in an infected ACL reconstruction would not affect the amount of post-operative tunnel widening. A case-control study was done. At a mean follow up of 10 months (range 9-11 months) eight patients with septic arthritis following ACL reconstruction (group A) were radiologically reviewed using a CT scan and the diameters of femoral and tibial tunnels were measured. The results were compared with a control group (B) of uncomplicated ACL reconstruction cases operated by the same surgeon using the same technique. Although patients of Group A experienced a bigger amount of tunnel enlargement than patients of group B both on femoral (9.53 +/- 1.07 vs. 9.35 +/- 1.52 mm) and tibial side (10.07 +/- 1.3 vs. 9.92 +/- 0.74 mm), no clinical or statistically significant differences were detected between the groups (P > 0.05). No significant tunnel enlargement could be detected in patients of group A when compared with patients of group B. This seems to minimize the role of biological factors contributing to tunnel widening.

Arthroscopic reconstruction of the anterior cruciate ligament using bone-patellar tendon-bone autograft: a minimum 10-year follow-up

BACKGROUND

Anterior cruciate ligament reconstruction surgery and technique have changed over the past decade.

HYPOTHESIS

Modern arthroscopic management of an anterior cruciate ligament tear using patellar tendon autograft offers a high patient satisfaction rate and good clinical results over the long term. However, it may be associated with osteoarthritis changes over time.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

In 1992, a prospective computerized database of anterior cruciate ligament reconstruction was established. Since that time, 101 anterior cruciate ligament arthroscopic reconstructions performed at our institution have been observed. Inclusion criteria were as follows: reconstruction with bone-patellar tendon-bone graft, a minimum 10-year follow-up, a standardized operative procedure, and no previous anterior cruciate ligament repair or associated ligament lesions. Before surgery, the mean age of the patients was 28.8 years +/- 8.3 (mean +/- SD). The follow-up assessment was established using the International Knee Documentation Committee (IKDC) 2000 form and quantitative laxity testing with a KT-1000 arthrometer. The joint space narrowing assessment used the IKDC score with a 30 degrees posteroanterior weightbearing view.

RESULTS

Mean follow-up was 11.6 +/- 0.8 years. Nine graft ruptures occurred. The satisfaction rate was excellent (90%). Seventy patients (74%) were still actively participating in sports. The mean subjective IKDC 2000 score was 90.5 +/- 8.8 points. The IKDC score was statistically correlated to laxity, time from injury, and osteoarthritis development at final follow-up. Ninety-one percent of patients were graded A or B according to the overall IKDC score. The radiological assessment reported osteoarthritis development in 17.8% of patients, and 39% showed radiological changes. Osteoarthritis was correlated with body mass index (P = .01) and age at follow-up (P = .006). In a selected population without meniscus and articular cartilage injury, an osteoarthritis rate of only 8% was found. Conclusion Arthroscopic anterior cruciate ligament reconstruction using bone-patellar tendon-bone autograft resulted in high patient satisfaction levels and good clinical results after 10 years. Moreover, a high percentage of patients remained involved in sports activities, and anterior cruciate ligament reconstruction protected their meniscus from a secondary tear. However, knee osteoarthritis developed in 17.8% of patients so treated.

Radiological landmarks for placement of the tunnels in single-bundle reconstruction of the anterior cruciate ligament

There is little evidence examining the relationship between anatomical landmarks, radiological placement of the tunnels and long-term clinical outcomes following anterior cruciate ligament (ACL) reconstruction. The aim of this study was to investigate the reproducibility of intra-operative landmarks for placement of the tunnels in single-bundle reconstruction of the ACL using four-strand hamstring tendon autografts. Isolated reconstruction of the ACL was performed in 200 patients, who were followed prospectively for seven years with use of the International Knee Documentation Committee forms and radiographs. Taking 0% as the anterior and 100% as the posterior extent, the femoral tunnel was a mean of 86% (sd 5) along Blumensaat's line and the tibial tunnel was 48% (sd 5) along the tibial plateau. Taking 0% as the medial and 100% as the lateral extent, the tibial tunnel was 46% (sd 3) across the tibial plateau and the mean inclination of the graft in the coronal plane was 19 degrees (sd 5.5). The use of intra-operative landmarks resulted in reproducible placement of the tunnels and an excellent clinical outcome seven years after operation. Vertical inclination was associated with increased rotational instability and degenerative radiological changes, while rupture of the graft was associated with posterior placement of the tibial tunnel. If the osseous tunnels are correctly placed, single-bundle reconstruction of the ACL adequately controls both anteroposterior and rotational instability.

Strategies to improve anterior cruciate ligament healing and graft placement

Recent improvements in anterior cruciate ligament (ACL) reconstruction have been notable for strategies to improve ACL healing and to improve graft placements. The controversial choice of 1-bundle or 2-bundle grafts requires an advanced knowledge of native ACL insertional anatomy and an appreciation for the kinematic effects of graft placements. Understanding the limitations of surgical techniques to place tunnels is important. Once grafts are placed, new biologic strategies to promote intra-articular and intraosseous healing are evolving. Although these biologic engineering strategies are currently experimental, they are projected for clinical application in the near future.

Differences in the placement of the tibial tunnel during reconstruction of the anterior cruciate ligament with and without computer-assisted navigation

BACKGROUND

Next to graft fixation, correct positioning of the tibial and femoral tunnel is a deciding factor for the clinical result of anterior cruciate ligament reconstruction surgery. Computer-assisted navigation has been proposed as a method to improve tunnel positioning.

PURPOSE

To examine the differences in tibial tunnel placement between cruciate ligament operations using manual and computer-assisted navigation.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Between December 2003 and April 2004, 53 athletes underwent anterior cruciate ligament reconstruction surgery with arthroscopic press-fit technique. The first group (group N; 24 athletes) were operated on with the aid of a navigation system (OrthoPilot, Aesculap AG & Co. KG, Braun), and the second group (group M; 29 athletes) were "manually" operated on. A lateral radiograph of the knee at maximum extension was used to determine the exact position of the tibial tunnel four days postoperatively. In the measurements, the anterior and posterior boundaries of the tibial tunnel, as well as the center of the tibial tunnel in relation to the maximum tibia anteroposterior diameter were evaluated (indicated in percent). An analysis of the tibial tunnel position proportional to the slope of the intercondylar roof was done to determine intercondylar impingement (method according to Howell). The centers of the tibial tunnels were compared with the "optimal" position noted in previous studies. The standard deviation was determined for both groups to determine the variance of placement.

RESULTS

The anterior tibial tunnel border was 19.4 mm in group M (29.7%) and 21.2 mm in group N (32.2%) (P = .18). The center of the tibial tunnel was located at 24.6 mm in group M (35.6%) and at 26.6 mm in group N (40.3%) (P = .19). In group M, the posterior tibial tunnel position was located at 30.2 mm (46.2%), and in group N at 32.2 mm (49.1%) (P = .21). When comparing the centers of the tibial tunnels with the optimal 44% found in previous studies, the value for group M (37.6%) varied significantly, while group N (40.5%) did not. However, there was no significant difference in the range variance for either group; the standard deviation was 6.9% (4.3 mm) for group M and 5.9% (3.5 mm) for group N. One athlete showed moderate impingement in group N, and two athletes in group M.

CONCLUSION

Assisted navigation offers good support for correct placement of the tibial tunnel, although experienced surgeons can achieve essentially the same positioning as surgeons using computer-assisted navigation. Whether it is advisable to implement this procedure in daily surgical routine should be decided based on clinical results.

Arthrofibrosis of the knee

Better understanding of surgical timing, improved surgical technique, and advanced rehabilitation protocols has led to decreased incidence of motion loss after anterior cruciate ligament injury and reconstruction. However, motion loss from high-energy, multiligament injuries continues to compromise functional outcome. Prevention, consisting of control of inflammation and early motion, remains the key element in avoiding motion loss. However, certain techniques, such as manipulation under anesthesia in conjunction with arthroscopic lysis of adhesions, are reliable treatment options. Open surgical débridement is rarely necessary and should be considered only as a salvage procedure. A greater understanding of the pathogenesis of arthrofibrosis and related inflammatory mediators may result in novel therapies for treating the patient with motion loss.

The effect of accelerated, brace free, rehabilitation on bone tunnel enlargement after ACL reconstruction using hamstring tendons: a CT study

The mechanism of bone tunnel enlargement following anterior cruciate ligament (ACL) reconstruction is not yet clearly understood. Many authors hypothesized that aggressive rehabilitation protocols may be a potential factor for bone tunnel enlargement, especially in reconstructions performed with hamstrings autograft. The purpose of this study was to evaluate the effect of a brace free rehabilitation on the tunnel enlargement after ACL reconstruction using doubled semitendinosus and gracilis tendons (DGST): our hypothesis was that early post-operative knee motion increase the diameters of the tibial and femoral bone tunnels. Forty-five consecutive patients undergoing ACL reconstruction for chronic ACL deficiency were selected. All patients were operated by the same surgeon using autologous DGST and the same fixation devices. Patients with associated ligaments injuries and or severe chondral damage were excluded. The patients were randomly assigned to enter the control group (group A, standard post-operative rehabilitation) and the study group (group B, brace free accelerated rehabilitation). A CT scan was used to exactly determine the diameters of both femoral and tibial tunnels at various levels of lateral femoral condyle and proximal tibia, using a previously described method [17]. Measurements were done by an independent radiologist in a blinded fashion the day after the operation and at a mean follow-up of 10 months (range 9-11). Statistical analysis was performed using paired t-test. The mean femoral tunnel diameter increased significantly from 9.04 +/- 0.05 (post-operative) to 9.30 +/- 0.8 mm (follow-up) in group A and from 9.04 +/- 0.03 to 9.94 +/- 1.12 mm in group B. The mean tibial tunnel diameter increased significantly from 9.03 +/- 0.04 to 10.01 +/- 0.80 mm in group A and from 9.04 +/- 0.03 to 10.60 +/- 0.78 mm in group B. The increase in femoral and tunnel diameters observed in the study group was significantly higher than that observed in the control group. Our results suggest that bone tunnel enlargement after ACL reconstruction using hamstrings autograft can be increased by an accelerated, brace free, rehabilitation protocol.

Current concepts review: revision anterior cruciate ligament reconstruction

Failed anterior cruciate ligament (ACL) reconstruction presents a difficult clinical challenge. Successful revision ACL reconstruction depends on identifying the causes of failure and correcting technical or diagnostic errors. Failed ACL reconstruction may be either traumatic or atraumatic. Atraumatic failures may be attributable to technical errors, diagnostic errors, or failure of graft incorporation. Published outcomes of revision ACL reconstruction have been worse than for primary ACL reconstruction. The preoperative evaluation, surgical techniques, and clinical outcomes of revision ACL reconstruction are reviewed.

Bone tunnel enlargement after ACL reconstruction using autologous hamstring tendons: a CT study

PURPOSE

To evaluate prospectively the increase in the size of the tibial and femoral bone tunnel following arthroscopic anterior cruciate ligament (ACL) reconstruction with quadrupled-hamstring autograft.

METHODS

Twenty-five consecutive patients underwent arthroscopic ACL reconstruction with quadrupled-hamstring autograft. Preoperative clinical evaluation was performed using the Lysholm knee score, Tegner activity level, and International Knee Documentation Committee forms and a KT-1000 arthrometer (side to side). Computed tomography (CT) of the femoral and tibial tunnel was performed on the day after operation in all cases and at mean follow-up of 10 months (range 9-11 months).

RESULTS

All of the clinical evaluation scales performed showed an overall improvement. The postoperative anterior laxity difference was <3 mm in 16 patients (70%) and 3-5 mm in seven patients (30%). The mean average femoral tunnel diameter increased significantly (3%) from 9.04+/-0.05 mm postoperatively to 9.3+/-0.8 mm at 10 months; tibial tunnel increased significantly (11%) from 9.03+/-0.04 mm to 10+/-0.8 mm. There were no statistically significant differences between tunnel enlargement, clinical results, and arthrometer evaluation.

CONCLUSIONS

The rate of tunnel widening observed in this study seems to be lower than that reported in previous studies that used different techniques. We conclude that an anatomical surgical technique and a less aggressive rehabilitation process influenced the amount of tunnel enlargement after ACL reconstruction with doubled hamstrings.

Validation of the 65 degrees Howell guide for anterior cruciate ligament reconstruction

PURPOSE

To study in cadaver knees the position of the tibial tunnel in anterior cruciate ligament (ACL) reconstruction using the 65 degrees Howell guide (Arthrotek, Ontario, CA).

TYPE OF STUDY

Controlled laboratory study in vitro.

METHODS

Twenty-one fresh-frozen cadaver knees were used. The ACL was resected and its tibial attachment was demarcated. To drill the guidewire, we used the Howell 65 degrees tibial guide, which references off of the intercondylar roof in extension to avoid impingement. The intra-articular position of the wire was digitized with a digital camera and referred to a transverse axis passing through the over-the-back position and a sagittal axis passing through the lateral aspect of the medial spine. The percentage position of the wire within the ACL attachment was also calculated, taking the posterior and medial limits as the 0% positions.

RESULTS

All the wires were within the ACL attachment: 17 were in the ACL posterolateral bundle attachment and the other 4 in the anteromedial. The average distance of the wire from the transverse and sagittal axes was 12 mm (SD, 3 mm) anterior and 1 mm (SD, 1 mm) lateral, respectively. The wire was positioned at 38% (SD, 16%) of the length of the ACL attachment and at 40% (SD, 17%) of the width. Eighty percent of the wires were positioned at between 35% and 48% of the attachment length.

CONCLUSIONS

The 65 degrees Howell guide, which positions the tibial tunnel in extension to avoid roof impingement, ensures anatomic positioning of the graft on the tibial side and reproducibility can be expected.

CLINICAL RELEVANCE

This study proves that a commonly used drill guide succeeds in placing the ACL graft in the tibial anatomic attachment.

Computer-assisted navigation and anterior cruciate ligament reconstruction: accuracy and outcomes

As many as 175,000 anterior cruciate ligament (ACL) reconstructions are performed annually in the United States at a cost >1 billion dollars. Estimates of the rate of revision surgery are as high as 10%-20%, potentially resulting in as many as 35,000 revisions a year. In addition, errors that are not obvious at short-term or mid-term follow-up may have significant long--term effects in young patients. Studies have demonstrated that the majoriity of visions are related to technical errors, primarily tunnel placement. Computer-aided navigation systems provide enhanced precision in tunnel placement and may reduce the rate of revision surgery. Computer-aided systems can provide valuable data on rotational and translational laxity of the knee.

Arthroscopic treatment of the arthrofibrotic knee

The management of motion loss of the knee is challenging. A clear understanding of the pathoanatomic causes of motion loss is necessary to establish a careful and rational approach to treatment. Early recognition and physical therapy are effective for the majority of patients, but when these conservative measures fail, operative intervention is indicated. The purpose of this article is to outline a comprehensive approach to the arthroscopic evaluation and treatment of the arthrofibrotic knee. This technique is designed to allow the surgeon to systematically address the numerous causes of motion loss of the knee.

Recreating an acceptable angle of the tibial tunnel in the coronal plane in anterior cruciate ligament reconstruction using external landmarks

Although it is still unclear what the ideal angle of the tibial tunnel in the coronal plane should be when performing anterior cruciate ligament (ACL) reconstruction using the endoscopic single-incision technique, researchers have recently shown that erroneous placement of the tibial tunnel in the coronal plane can lead to graft laxity and loss of extension. We have developed a simple, reproducible technique to provide an acceptable angle of the tibial tunnel in the coronal plane when using the endoscopic single-incision ACL reconstruction technique by using bony landmarks. With the ACL guide parallel to the femur, the external portion of the tibial tunnel guide is rotated so that the guidewire starting point is made at the bisection of a line between the tibial tubercle and the posteromedial border of the tibia. We have confirmed this technique in cadaver studies with angles of the tibial tunnel less than 75 degrees in the coronal plane in all cases. In addition, we have used this technique with good clinical results in over 100 ACL reconstructions.

Comparison of expected vs. actual tunnel position in anterior cruciate ligament reconstruction

In a prospective blinded non-randomised cohort study, 32 patients were assessed following anterior cruciate ligament reconstruction using autograft middle-third bone-patellar tendon-bone, over a period of 10 months. Two experienced surgeons performed the procedures, one using an arthroscopically assisted technique (16 patients) and the other by mini-arthrotomy (16 patients). A comparison was made between the positions of the tunnels as perceived by the surgeon intra-operatively with the actual position as shown on the post-operative X-ray. An independent blinded observer made the latter assessment. Actual vs. expected tunnel placement was analysed using the coefficient of correlation. The anteroposterior femoral tunnel position indicated perfect correlation (R(2)=1.00, P=0), and on the lateral view showed good correlation (R(2)=0.55, P=0.005). However, the tibial tunnel position anteroposteriorly showed poor correlation (R(2)=0.14, P=0.22), and on the lateral view no correlation (R(2)=0.07, P=0.36). The ideal tibial tunnel position is controversial, and in this study, two tibial tunnels were just anterior to the acceptable position and one was posterior. Altogether these three, and one other, were in very different positions to that expected by the surgeon. Surgeons may consider that before drilling the tibial tunnel, intra-operative confirmation of the guide-wire position would be helpful.

Can a post-operative brace in slight hyperextension prevent extension deficit after anterior cruciate ligament reconstruction? A prospective randomised study

It has been our observation that post-operative anterior cruciate ligament (ACL) braces together with the post-operative bandages do not always allow the knee to reach full extension. In ten uninjured knees with known hyperextension, the knees were bandaged in the same way as after an ACL-reconstruction. The knees were then studied radiologically in a Hypex brace set at 0 degrees, -5 degrees and -10 degrees of knee extension. Not a single knee was found to be straight in the brace set at 0 degrees. At -5 degrees most of the knees were straight or in slight hyperextension. It took -10 degrees to get all knees straight or in hyperextension. In a prospective randomised study 44 patients who underwent an arthroscopic ACL-reconstruction with a bone patellar tendon bone graft were randomised to use either a brace set at -5 degrees or a straight brace (0 degrees ) for at least the first three postoperative weeks. Before and three months after surgery range of motion was determined, using a goniometer with long arms, and sagittal knee laxity was measured with a KT-2000 arthrometer at manual max. Pre- and post-operative pain was evaluated with the Visual Analogue Scale (VAS). The same examiner (blindfolded to what type of brace was used) performed all the measurements. At three months, two of the 22 patients with the brace set at -5 degrees and twelve of the 22 patients with the straight brace had a loss of full extension of 2 degrees or more ( p<0.001). No significant differences were found between the groups in terms of knee flexion, sagittal knee laxity or post-operative pain. Although extension deficit after ACL-reconstruction can be prevented also in other ways, a Hypex brace set at -5 degrees seems to be an easy way of ensuring full knee extension.

Effect of the angle of the femoral and tibial tunnels in the coronal plane and incremental excision of the posterior cruciate ligament on tension of an anterior cruciate ligament graft: an in vitro study

BACKGROUND

High tension in an anterior cruciate ligament graft adversely affects both the graft and the knee; however, it is unknown why high graft tension in flexion occurs in association with a posterior femoral tunnel. The purpose of the present study was to determine the effect of the angle of the femoral and tibial tunnels in the coronal plane and incremental excision of the posterior cruciate ligament on the tension of an anterior cruciate ligament graft during passive flexion.

METHODS

Eight cadaveric knees were tested. The angle of the tibial tunnel was varied to 60 degrees, 70 degrees, and 80 degrees in the coronal plane with use of three interchangeable, low-friction bushings. The femoral tunnel, with a 1-mm-thick posterior wall, was drilled through the tibial tunnel bushing with use of the transtibial technique. After the graft had been tested in all three tibial bushings with one femoral tunnel, the femoral tunnel was filled with bone cement and the tunnel combinations were tested. Lastly, the graft was replaced in the 80 degrees femoral and tibial tunnels, and the tests were repeated with excision of the lateral edge of the posterior cruciate ligament in 2-mm increments. Graft tension, the flexion angle, and anteroposterior laxity were recorded in a six-degrees-of-freedom load-application system that passively moved the knee from 0 degrees to 120 degrees of flexion.

RESULTS

The graft tension at 120 degrees of flexion was affected by the angle of the femoral tunnel and by incremental excision of the posterior cruciate ligament. The highest graft tension at 120 degrees of flexion was 169 +/- 9 N, which was detected with the graft in the 80 degrees femoral and 80 degrees tibial tunnels. The lowest graft tension at 120 degrees of flexion was 76 +/- 8 N, which was detected with the graft in the 60 degrees femoral and 60 degrees tibial tunnels. The graft tension of 76 N at 120 degrees of flexion with the graft in the 60 degrees femoral and 60 degrees tibial tunnels was closer to the tension in the intact anterior cruciate ligament. Excision of the lateral edge of the posterior cruciate ligament in 2 and 4-mm increments significantly lowered the graft tension at 120 degrees of flexion without changing the anteroposterior position of the tibia.

CONCLUSIONS

Placing the femoral tunnel at 60 degrees in the coronal plane lowers graft tension in flexion. Our results suggest that high graft tension in flexion is caused by impingement of the graft against the posterior cruciate ligament, which results from placing the femoral tunnel medially at the apex of the notch in the coronal plane.

Impingement pressure and tension forces of the anterior cruciate ligament

This study examined the impingement behavior of the uninjured ACL and the impingement pressure and tension forces of the ACL to draw conclusions for ACL reconstructions. A miniature pressure sensor was inserted between the ACL and the intercondylar roof of 15 knees of human cadavers before and after a 3-mm notch roof resection (thickness of the sensor); tension of the ACL was measured after attaching the tibial insertion to a load cell. A long-arm goniometer was used to determine corresponding extension angles. The beginning of contact of the ACL with the notch roof was between -1 and -2 degrees of knee extension. Pressure for full passive extension was 855.6+/-279.1 and 346.4+/-287.7 kPa, and ACL tension averaged 101.9+/-38.4 N. Tension forces in passive hyperextension were higher than those detected when a 200-N Lachman test was performed (83.5+/-25.1 N). There was a significant correlation between extension capability and impingement pressure. Impingement of the ACL was detected in all knees. Full passive extension exerts biomechanical pressure and tension on the ACL. Tension forces of the ACL are higher in passive hyperextension than during a Lachman test with 200 N. The impingement behavior found for the uninjured ACL is simulated in an ACL reconstruction when the center tibial tunnel position is used.

Complications in anterior cruciate ligament surgery

There are many potential problems associated with ACL surgery; however, careful attention to detail can prevent problems from occurring or provide corrective options in the event they do occur. Multiple backup options are not only desirable but also essential to a successful outcome. By following these guidelines, ACL surgery can have good long-term results and return the recreational or higher-level athlete to sports participation.

Scientific justification and technique for anterior cruciate ligament reconstruction using autogenous and allogeneic soft-tissue grafts

The DLSTG is the strongest and stiffest autogenous graft source available for reconstruction of the torn anterior cruciate ligament. Harvest morbidity is low compared with other autogenous graft sources, such as the patellar bone-tendon-bone graft. Soft-tissue allografts provide an excellent alternative for patients requiring revision surgery or for patients who want to avoid any morbidity associated with autogenous graft harvest. Successful use of any soft-tissue graft source, however, relies on precise placement of the tibial and femoral tunnels to prevent roof and PCL impingement and to restore tensile behavior in the graft tissue similar to the native ACL. The use of high-strength, high-stiffness fixation devices that secure the graft at the end of the tunnel promote tendon tunnel healing, restore stability without high graft tensioning, and allow safe, aggressive rehabilitation. The Bone Mulch Screw/WasherLoc screw system provides the surgeon with a consistent, reproducible technique that restores stability and function to the ACL-deficient knee using a soft-tissue graft in both males and females.

Revision anterior cruciate ligament reconstruction

Revision ACL surgery is indicated in patients who present with pathologic anterior laxity on clinical examination that reproduces their symptoms of instability during activities of daily living or athletic activities. The goals of the revision ACL surgery are to stabilize the knee, prevent further injury to the articular cartilage and menisci, and maximize the patient's function. Successful revision ACL surgery requires a thorough preoperative evaluation, including a detailed history, physical examination, and radiographic evaluation. Preoperative planning begins with a determination of the mechanisms of failure for the initial ACL reconstruction. Often a primary, as well as secondary cause, for failure can be identified. The determination of the cause of failure is the first step in a carefully-constructed treatment plan, which includes consideration of skin incisions to be used, method of graft removal, hardware removal, the need for a staged procedure or concomitant surgery, graft material selection, tunnel placement, graft fixation, and postoperative rehabilitation protocol. Despite the most meticulous planning, unanticipated findings may be encountered in the operating room, and the preoperative plan should have enough flexibility to accommodate these developments. Finally, it is crucial to counsel the patient preoperatively to limit his or her expectations regarding their surgical outcome. Given the complexity of revision ACL reconstruction, patient expectations must be adjusted to realistically match the potential for success. With proper planning, attention to detail, and appropriate patient expectations, revision ACL surgery can result in a beneficial and satisfying patient outcome.

Motion loss after ligament injuries to the knee. Part I: causes

Motion loss continues to be a difficult complication after ligament injury and surgery to the knee. A better understanding of the pathoanatomic causes of motion loss can lead to improved prevention and treatment strategies. When motion loss does occur, early recognition and appropriate treatment can be expected to restore motion and improve function in most patients. Treatment options, although varied, should improve outcome when implemented appropriately. This article is composed of two parts. The first part reviews the current concepts on definitions, incidence, and causes of motion loss. In the second part, to be published later, current strategies on prevention and treatment of motion loss after ligament injury to the knee are reviewed. Emphasis is placed on risk factors and prevention as well as on diagnosis and treatment. The article summarizes the latest information from the basic sciences as well as clinical studies on the problem of motion loss of the knee and attempts to provide a rational approach to these difficult clinical problems.

The relationship between the angle of the tibial tunnel in the coronal plane and loss of flexion and anterior laxity after anterior cruciate ligament reconstruction

Tension in an anterior cruciate ligament graft is greater with the knee in flexion when the angle of the tibial tunnel in the coronal plane is vertical or more perpendicular to the medial joint line of the tibia; however, the relationship of the angle of the tibial tunnel to knee function has not been studied. Greater graft tension may limit knee flexion or stretch the graft and increase anterior laxity. Five surgeons treated 119 subjects by reconstructing a torn anterior cruciate ligament using a double-looped semitendinosus and gracilis graft and a standardized technique. The femoral tunnel was drilled through the tibial tunnel. Radiographs were analyzed for tibial tunnel placement and a clinical evaluation was made 4 months postoperatively. Knees were assigned to subgroups according to the angle of the tibial tunnel in the coronal plane (65 degrees to 69 degrees, 70 degrees to 74 degrees, 75 degrees to 79 degrees, 80 degrees to 84 degrees, and 85 degrees to 89 degrees), with the angle of the latter subgroup being most vertical. Loss of flexion increased significantly from 0.5 degrees to 6.5 degrees and anterior laxity increased significantly from 0.5 to 2.2 mm as the tunnel angle was increased. The average angle of the tibial tunnel varied significantly, 11 degrees between surgeons (range, 69 degrees to 80 degrees). We found a tibial tunnel angle of 75 degrees or more is associated with greater loss of flexion and anterior laxity. Surgeons do not drill the angle of the tibial tunnel in the coronal plane accurately. We now routinely drill the tibial tunnel at an angle of 65 degrees to 70 degrees in the coronal plane because it may reduce loss of flexion and anterior laxity.

An audit of tunnel position in anterior cruciate ligament reconstruction

We audited 114 primary anterior cruciate ligament (ACL) reconstructions. Notes were reviewed and tunnel positions assessed on lateral and AP radiographs. A literature review established optimal tunnel position. Sixteen surgeons performed 57 arthroscopic and 57 open reconstructions, using 24 hamstring and 90 bone-tendon-bone autografts. Eighty-five sets of radiographs were available for review. Sixty-five percent of femoral tunnels and 59% of the tibial tunnels were malpositioned in the sagittal plane. Guidelines for best practice are required for key procedures in each speciality. Tunnel position in ACL reconstruction can be easily measured and should be correct in at least 90% of cases.