Long-term study of anterior cruciate ligament reconstruction for chronic instability using the central one-third patellar tendon and a lateral extraarticular tenodesis

Effect of patellar tendon shortening on tracking of the patella

BACKGROUND

Although 10% postoperative patellar tendon shortening after bone-patellar tendon-bone autograft reconstruction of the anterior cruciate ligament has been reported, there are no published studies assessing the effect of shortening on patellofemoral joint biomechanics under physiological loading conditions.

PURPOSE

To investigate the influence of patellar tendon shortening on patellofemoral joint biomechanics.

STUDY DESIGN

Controlled laboratory study.

METHODS

The authors evaluated the patellofemoral contact area, the location of contact, and the patellofemoral joint reaction force and contact stresses in 7 cadaveric knees before and after 10% patellar tendon shortening. Shortening was achieved using a specially designed device. Experimental conditions simulating those occurring during level walking were employed: physiological quadriceps loads and corresponding angles of tibial rotation were applied at 15 degrees , 30 degrees , and 60 degrees flexion of the knee. Patellofemoral joint contact areas were measured before and after shortening using the silicone oil-carbon black powder suspension squeeze technique.

RESULTS

After patellar tendon shortening, patellofemoral joint contact areas were displaced proximally on the patellar surface and distally on the femoral surface. Although the contact area increased by 18% at 15 degrees of knee flexion (P = .04), no significant change occurred at 30 degrees or 60 degrees of knee flexion (P > .05). Patellofemoral contact stress remained unchanged after patellar tendon shortening (P > .05) at each flexion angle.

CONCLUSION

Our results suggest that a 10% shortening of the patellar tendon does not alter patellar contact stresses during locomotion. It is not clear whether apparent changes in contact location in all positions and contact area at 15 degrees would have clinical consequences.

Treatment of anterior cruciate ligament injuries, part I

Anterior cruciate ligament injuries are common among athletes. Although the true natural history remains unclear, anterior cruciate ligament injuries are functionally disabling; they predispose the knee to subsequent injuries and the early onset of osteoarthritis. This article, the first in a 2-part series, was initiated with the use of the PubMed database and a comprehensive search of articles that appeared between January 1994 to the present, using the keywords anterior cruciate ligament. A total of 3810 citations were identified and reviewed to determine the current state of knowledge about the treatment of these injuries. Articles pertaining to the biomechanical behavior of the anterior cruciate ligament, the prevalence of anterior cruciate ligament injury, the natural history of the anterior cruciate ligament-deficient knee, injuries associated with anterior cruciate ligament disruption, risk factors for anterior cruciate ligament injury, indications for treatment of anterior cruciate ligament injuries, and nonoperative and operative treatments were obtained, reviewed, and served as the basis for part I. Part II, to be presented in another issue of this journal, includes technical aspects of anterior cruciate ligament surgery, bone tunnel widening, graft healing, rehabilitation after reconstruction, and the effect of sex, age, and activity level on the outcome of surgery. Our approach was to build on prior reviews and to provide an overview of the literature for each of the before-mentioned areas of study by summarizing the highest level of scientific evidence available. For the areas that required a descriptive approach to research, we focused on the prospective studies that were available; for the areas that required an experimental approach, we focused on the prospective, randomized controlled trials and, when necessary, the highest level of evidence available. We were surprised to learn that considerable advances have been made during the past decade regarding the treatment of this devastating injury.

Estimation of ACL forces by reproducing knee kinematics between sets of knees: A novel non-invasive methodology

In situ force in the anterior cruciate ligament (ACL) has been quantified both in vitro in response to relatively simple loads by means of robotic technology, as well as in vivo in response to more complex loads by means of force transducers and computational models. However, a methodology has been suggested to indirectly estimate the in situ forces in the ACL in a non-invasive, non-contact manner by reproducing six-degree of freedom (six-DOF) in vivo kinematics on cadaveric knees using a robotic/UFS testing system. Therefore, the objective of this study was to determine the feasibility of this approach. Kinematics from eight porcine knees (source knees) were collected at 30 degrees , 60 degrees , and 90 degrees of flexion in response to: (1) an anterior load of 100 N and (2) a valgus load of 5 N m. The average of each kinematic data set was reproduced on a separate set of eight knees (target knees). The in situ forces in the ACL were determined for both sets of knees and compared. Significant differences (rho<0.05) were found between the source knees and the target knees for all flexion angles in response to an anterior load. However, in response to valgus loads, there was no significant difference between the source knees and the target knees at 30 degrees and 90 degrees of flexion. It was noted that there was a correlation between anterior knee laxity (the distance along the displacement axis from the origin to the beginning of the linear region of the load-displacement curve) and internal-external rotation. These data suggest that in order to obtain reproducible results one needs to first match knees to knees with comparable anterior knee laxity. Thus, an estimate of the in situ forces in the ACL during in vivo activities might be obtainable using this novel methodology.

Long-term follow-up after primary repair of the anterior cruciate ligament: clinical and radiological evaluation 15-23 years postoperatively

INTRODUCTION

We have previously reported results after 2-5 and 5-10 years follow-up of repair of acute anterior cruciate ligament (ACL) ruptures by suturing. Reports of results after more than 10 years are rare.

MATERIALS AND METHODS

A total of 140 patients were operated on in the period 1975-1983 (age range 13-71 years, median 28 years) by the modified Palmer technique. Only 2 meniscus resections and 4 meniscectomies were performed at the primary operation; while 28 menisci were sutured. At follow-up,12 patients were dead. Eighteen patients (13%) underwent repeat operations for secondary instability. Of the remaining 110 patients, 81 appeared for follow-up.

RESULTS

Only 6 secondary meniscus resections were performed, all in the group of 18 patients operated on again for instability. No secondary meniscus surgery was performed on the 81 patients who appeared for follow-up. The median Lysholm score was 88, and 58 of the 81 patients (71%) classified their total knee function as good or excellent. By KT-1000 testing, 33 (41%) patients had less than 3 mm anterior instability, 29 (36%) had 3-5 mm instability, and 17 (21%) had more than 5 mm. With 18 patients from the total of 128 living patients re-operated for instability, we estimate the rate of total failure of stability as 27%. Radiological osteoarthritis grade C was present in 8 operated and 2 control knees, while only 1 operated knee revealed osteoarthritis grade D. Thirty-four operated and 20 control knees had grade B. Osteoarthritis was correlated to more advanced age at injury, while correlation to function could not be proven. Radiographs were obtained of 61 patients at follow-up.

CONCLUSIONS

Some 50% of patients had stable or slightly unstable knees, and 40% good or excellent function according to the Lysholm score. Re-operation for instability was more frequent in younger patients, while ostearthritis was more frequent in older patients. The rate of meniscus resection or extirpation was low. Open repair by suture is no longer recommended. Further research is indicated on the possible use of refixation of the ruptured ACL by arthroscopy.

Reinforced iliotibial tenodesis for chronic anterolateral instability of the knee: a 6-year follow-up

Reinforced iliotibial tenodesis is an extra-articular procedure to eliminate anterolateral instability of an anterior cruciate ligament-deficient knee. The procedure carries a low complication rate and offers an easy rehabilitation program. This study evaluated the use of reinforced iliotibial tenodesis in a select group of 52 patients with a mean age of 41 years (range: 38-50 years). Obese patients, professional athletes, and patients with more complex injuries (eg, concomitant posterior cruciate or medial collateral ligament injuries) were excluded. Results are encouraging after a mean follow-up of 6 years (range: 2-10 years). Although 24 patients had a positive anterior drawer or Lachman test, none had a positive pivot test. In addition, all patients reported giving way was eliminated after surgery.

The effect of anterior cruciate ligament reconstruction on knee joint kinematics under simulated muscle loads

BACKGROUND

Numerous studies have investigated anterior stability of the knee during the anterior drawer test after anterior cruciate ligament reconstruction. Few studies have evaluated anterior cruciate ligament reconstruction under physiological loads.

PURPOSE

To determine whether anterior cruciate ligament reconstruction reproduced knee motion under simulated muscle loads.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight human cadaveric knees were tested with the anterior cruciate ligament intact, transected, and reconstructed (using a bone-patellar tendon-bone graft) on a robotic testing system. Tibial translation and rotation were measured at 0 degrees, 15 degrees, 30 degrees, 60 degrees, and 90 degrees of flexion under anterior drawer loading (130 N), quadriceps muscle loading (400 N), and combined quadriceps and hamstring muscle loading (400 N and 200 N, respectively). Repeated-measures analysis of variance and the Student-Newman-Keuls test were used to detect statistically significant differences between knee states.

RESULTS

Anterior cruciate ligament reconstruction resulted in a clinically satisfactory anterior tibial translation. The anterior tibial translation of the reconstructed knee was 1.93 mm larger than the intact knee at 30 degrees of flexion under anterior load. Anterior cruciate ligament reconstruction overconstrained tibial rotation, causing significantly less internal tibial rotation in the reconstructed knee at low flexion angles (0 degrees-30 degrees) under muscle loads (P < .05). At 30 degrees of flexion, under muscle loads, the tibia of the reconstructed knee was 1.9 degrees externally rotated compared to the intact knee.

CONCLUSIONS

Anterior cruciate ligament reconstruction may not restore the rotational kinematics of the intact knee under muscle loads, even though anterior tibial translation was restored to a clinically satisfactory level under anterior drawer loads. These data suggest that reproducing anterior stability under anterior tibial loads may not ensure that knee joint kinematics is restored under physiological loading conditions.

CLINICAL RELEVANCE

Decreased internal rotation of the knee after anterior cruciate ligament reconstruction may lead to increased patellofemoral joint contact pressures. Future anterior cruciate ligament reconstruction techniques should aim at restoring 3-dimensional knee kinematics under physiological loads.

Contribution of biomechanics, orthopaedics and rehabilitation: the past present and future

Biomechanics is a field that has a very long history. From its beginnings in ancient Chinese and Greek literature, the field of orthopaedic biomechanics has grown in the areas of biomechanics of bone, articular cartilage, soft tissues, upper extremities, spine and so on. Bioengineers in collaboration with orthopaedic surgeons have applied biomechanical principles to study clinically relevant problems, improving patient treatment and outcome. In the past 30 years, my colleagues and I have focused our research on the biomechanics of musculoskeletal soft tissues, ligaments and tendons in particular. Therefore, in this review article, the function of the knee ligaments and the associated homeostatic responses secondary to immobilisation and exercise will be described. Research on healing of the medial collateral ligament (MCL) of the knee and possible future approaches in improving the healing of the knee ligaments will be presented. Finally, improvement of the understanding of ligament reconstruction, specifically of the anterior cruciate ligament (ACL), through the use of robotics technology will be included. Throughout the manuscript, specific scientific findings that have guided or changed the clinical management of injury to these soft tissues will be emphasised.

Knee stability and graft function after anterior cruciate ligament reconstruction: a comparison of a lateral and an anatomical femoral tunnel placement

BACKGROUND

Locations of femoral tunnels for anterior cruciate ligament replacement grafts remain a subject of debate.

HYPOTHESIS

A lateral femoral tunnel placed at the insertion of the posterolateral bundle of the anterior cruciate ligament can restore knee function comparably to anatomical femoral tunnel placement.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten cadaveric knees were subjected to the following external loading conditions: (1) a 134-N anterior tibial load and (2) combined rotatory loads of 10-N.m valgus and 5-N.m internal tibial torques. Data on resulting knee kinematics and in situ force of the intact anterior cruciate ligament and anterior cruciate ligament graft were collected using a robotic/universal force-moment sensor testing system for (1) intact, (2) anterior cruciate ligament-deficient, (3) anatomical double-bundle reconstructed, and (4) laterally placed single-bundle reconstructed knees.

RESULTS

In response to anterior tibial load, anterior tibial translation and in situ force in the graft were not significantly different between the 2 reconstructions except at high knee flexion. For example, at 90 degrees of knee flexion, anterior tibial translation was 6.1 +/- 2.3 mm for anatomical double-bundle reconstruction and 7.6 +/- 2.6 mm for laterally placed single-bundle reconstruction (P < .05). In response to rotatory loads, there were no significant differences between the 2 reconstruction procedures (4.8 +/- 2.4 mm vs 4.8 +/- 3.0 mm in anterior tibial translation at 15 degrees of knee flexion, P > .05).

CONCLUSION

Lateral tunnel placement can restore rotatory and anterior knee stability similarly to an anatomical reconstruction when the knee is near extension. However, the same is not true when the knee is at high flexion angles.

CLINICAL RELEVANCE

To reproduce the complex function of the anterior cruciate ligament, reproducing both bundles of the anterior cruciate ligament may be necessary.

Reconstrução do LCA com o uso dos tendões dos músculos flexores mediais do joelho e fixação femoral com o sistema de Rigidifix®: relato preliminar

O autor descreve a técnica de reconstrução do LCA no tratamento das instabilidades anterior do joelho, utilizando os tendões dos músculos flexores mediais do joelho (semitendíneo e grácil), fixados no fêmur pelo sistema de Rigidfix®; e na tíbia, com parafuso de interferência absorvível, através de um estudo preliminar de 54 joelhos operados. Na avaliação final pela escala de Lysholm os pacientes evoluíram de 46 pontos no pré-operatório para 92 pontos no pós-operatório.

Experimental and Computational Modeling of Joint and Ligament Mechanics

Quantitative data on the mechanics of diarthrodial joints and the function of ligaments are needed to better understand injury mechanisms, improve surgical procedures, and develop improved rehabilitation protocols. Therefore, experimental and computational approaches have been developed to determine joint kinematics and the in-situ forces in ligaments and their replacement grafts using human cadaveric knee and shoulder joints. A robotic/universal force-moment sensor testing system is used in our research center for the evaluation of a wide variety of external loading conditions to study the function of ligaments and their replacements; it has the potential to reproduce in-vivo joint motions in a cadaver knee. Two types of computational models have also been developed: a rigid body spring model and a displacement controlled spring model. These computational models are designed to complement and enhance experimental studies so that more complex loading conditions can be examined and the stresses and strains in the soft tissues can be calculated. In the future, this combined approach will improve our understanding of these joints and soft tissues during in-vivo activities and serve as a tool to aid surgical planning and development of rehabilitation protocols.

Long-term outcome of MacIntosh reconstruction of chronic anterior cruciate ligament insufficiency using fascia lata

The purpose of this study was to assess the long-term outcome of the MacIntosh lateral-substitution over-the-top anterior cruciate ligament (ACL) reconstruction in 82 patients (84 knees) at an average follow-up of 9.8 years. In this retrospective cohort study patients were evaluated with subjective questionnaires and by clinical and radiographic examination. Using the Lysholm score, 17 knees were rated excellent, 35 good, 19 fair, and 13 poor. The pivot shift test was negative in 74 patients. Altogether, 30 knee radiographs were evaluated. The mean Hospital for Special Surgery ACL radiographic score was 20.9. There was a non-significant association between the radiographic score and the Lysholm score and between a worsening radiographic score and increasing time from injury. The MacIntosh lateral-substitution over-the-top ACL reconstruction shows results comparable to those of previously reported long-term studies. Although endoscopically assisted intraarticular reconstructions with faster rehabilitation protocols have now become popular, this procedure may be considered in patients needing an intra- and extraarticular reconstruction in whom cosmesis is not an issue.

The role of periosteal flap in the prevention of femoral widening in anterior cruciate ligament reconstruction using hamstring tendons

Tunnel widening in anterior cruciate ligament reconstruction has been reported for many years, whatever the type of plasty (allo- or autograft) or graft (patellar or hamstring tendons). Recently, the hypothesis has been formulated that widening would be responsible for later laxity of the knees. Micromobility of the graft or biological factors are classically responsible for the enlargement. In order to improve the biological conditions around the graft within the tunnel, we have developed a surgical technique using a periosteal flap. The periosteal flap is harvested at the superior and medial metaphysis of the tibia and wrapped around the proximal part of the four strands of gracilis and semitendinosus tendons near the outlet of the femoral tunnel. Forty-one patients with isolated rupture of the ACL were included in a prospective and randomized study: the first group of 20 patients had femoral fixation by Transfix and resorbable screw, the second group of 21 patients had femoral fixation by Transfix and periosteal flap. The diameters of the tunnel were measured between the sclerotic margins at the tunnel entrance and 1 cm above, and compared to the peroperative drill size. The percentage change in diameter was calculated as: (tunnel diameter-drill size)/drill size. The two groups of patients were comparable as to gender, side, age, KT-1000 side to side difference, femoral tunnel diameter and follow-up. At 2.5 months and 11 months postoperatively on average, there was a significant reduction of enlargement at the outlet of the tunnel with the use of a periosteal flap but widening was constant.

Results of repeat meniscal repair

BACKGROUND

The efficacy of repeat repair of retorn menisci has not been demonstrated.

PURPOSE

To document clinical and radiographic results of repeat repair of retorn menisci that had previously undergone primary repair.

STUDY DESIGN

Uncontrolled retrospective review.

METHODS

Eighteen consecutive repeat meniscal repairs were performed over an 11-year period.

RESULTS

Fourteen of 18 patients (13 repeat meniscal repairs and 1 second repeat meniscal repair) had clinically intact menisci and were available for a mean follow-up of 7.33 years (range, 3.25 to 13.75). The average durability of the initial repair was 3.46 years (range, 0.17 to 14.67). Five patients sustained a tear at the site of rerepair; one underwent second repeat repair of the meniscus and the other four patients underwent partial meniscectomy. The mean Lysholm score for the remaining 14 patients was 82.1 (range, 38 to 100), and the mean Tegner score was 5.6 (range, 2 to 8). On the International Knee Documentation Committee rating scale, five knees received an overall rating of normal; six, nearly normal; and three, abnormal. Radiographs revealed grade 0 changes (normal) in five of the involved knee compartments and grade I changes (sclerosis or mild narrowing measuring 1 to 2 mm) in the remaining five.

CONCLUSIONS

Repeat repair of retorn menisci had a 72% survival rate with relief of symptoms and return to high levels of function.

Anterior cruciate ligament reconstruction: allograft versus autograft

PURPOSE

This study was performed to compare the minimal 2-year outcome of anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon-bone (BPTB) allografts versus autografts, both augmented with an iliotibial band tenodesis.

TYPE OF STUDY

Retrospective review.

METHODS

Forty-six of 52 BPTB ACL reconstructions using allografts and 33 of 37 BPTB ACL reconstructions using autografts were followed up at a mean of 2.75 and 3.36 years, respectively. All patients had an iliotibial band tenodesis. Evaluations included the Lysholm II scale, a questionnaire, physical examination findings, and KT-1000 arthrometry.

RESULTS

No statistically significant differences were seen between groups in Lysholm II scores or in any subjective category. Most patients (91% allograft; 97% autograft) had good to excellent Lysholm II scores. Sixty-five percent of allograft patients and 73% of autograft patients returned to their preinjury activity level. More allograft patients complained of retropatellar pain (16% v 9% for autograft patients). Fifty-three percent of allograft patients versus 23% of autograft patients had a flexion deficit of 5 degrees or more when compared with the normal contralateral side. When comparing KT-1000 side-to-side differences, we found no significant differences between groups. Ninety-one percent of both groups had maximum side-to-side differences less than 5 mm. Three allograft patients (6.5%) had traumatic ruptures at 12, 19, and 43 months postoperatively versus none in the autograft group. All three allograft patients who sustained postoperative traumatic ruptures had received fresh frozen, nonirradiated allografts.

CONCLUSIONS

Results of ACL reconstruction using allografts or autografts augmented with an iliotibial band tenodesis were comparable. The BPTB autograft should remain the gold standard, although the BPTB allograft in ACL reconstruction is a reasonable alternative.

Effects of notchplasty and femoral tunnel position on excursion patterns of an anterior cruciate ligament graft

PURPOSE

Errors in femoral tunnel placement in anterior cruciate ligament (ACL) reconstruction can cause excessive length changes in the graft during knee flexion and extension, resulting in graft elongation during the postoperative period. To improve the accuracy of tunnel placement and to avoid graft impingement, a notchplasty is commonly performed. The purpose of this study was to determine the effects of varying the position of the femoral tunnel and of performing a 2-mm notchplasty of the lateral femoral condyle and roof of the intercondylar notch on excursion patterns of a bone-patellar tendon-bone graft.

TYPE OF STUDY

Biomechanical cadaveric study.

METHODS

A cylindrical cap of bone, containing the tibial insertion of the ACL, was mechanically isolated in 15 fresh-frozen cadaveric specimens using a coring cutter. The bone cap was attached to an electronic isometer that recorded displacement of the bone cap relative to the tibia as the knee was taken through a 90 degrees range of motion. After native ACL testing, the proximal end of a 10-mm bone-patella tendon-bone graft was fixed within femoral tunnels drilled at the 10-, 11-, and 12-o'clock (or 2-, 1-, and 12-o'clock) positions within the notch. The distal end of the graft was attached to the isometer. Testing was then completed at each tunnel position before and after notchplasty.

RESULTS

Before notchplasty, mean graft excursions at the 10- or 2-, 11- or 1-, and 12-o'clock tunnels were not significantly different from the excursions of the native ACL or each other. After a 2-mm notchplasty, mean graft excursions at the 3 tunnel locations were not sigificantly different from each other but were greater than mean graft excursions before notchplasty. After notchplasty, all grafts tightened during knee flexion.

CONCLUSIONS

Although errors in placement along the arc of the intercondylar notch did not significantly affect graft excursion patterns, the apparent graft tightening with knee flexion that was observed for all 3 tunnel positions after notchplasty suggests that graft forces would increase with knee flexion over this range. This would indicate that as little amount of bone as possible should be removed from the posterior portion of the intercondylar notch in ACL reconstruction.

Ligament grafts become more susceptible to creep within days after surgery: evidence for early enzymatic degradation of a ligament graft in a rabbit model

Clinical evidence suggests that some ligament grafts stretch after surgery. Our purpose in this study was to quantify early postoperative creep behavior of ligament autografts in an animal model, and to explore potential mechanisms of that behavior. 38 New Zealand white rabbits underwent a unilateral, fresh, anatomic medial collateral ligament (MCL) autograft procedure and were killed immediately (time-zero), at 2 days, 3 weeks, or 8 weeks after surgery (n = 7-11 in each group). We compared the creep behavior of the autografts to normal MCLs (n = 8). An additional 7 MCL specimens were incubated for 2 days in a low concentration collagenase solution and then similarly creep-tested. All grafts were slower to recover their original length after creep than either normal ligaments or time-zero controls. These grafts started to become more vulnerable to elongation in cyclic and static creep tests within 2 days of surgery, compared to time-zero controls. This vulnerability to creep increased over the next 3 weeks, and was maintained at 8 weeks of healing. 2-day collagenase-soaked MCL specimens had the same creep strains as the 2-day autografts. These results suggest that even fresh anatomic ligament autografts become vulnerable to creep within a few days after surgery by mechanisms that may involve degradative enzymes such as collagenase.

The effectiveness of reconstruction of the anterior cruciate ligament with hamstrings and patellar tendon . A cadaveric study comparing anterior tibial and rotational loads

BACKGROUND

The objective of this study was to evaluate the effectiveness of reconstructions of the anterior cruciate ligament to resist anterior tibial and rotational loads. We hypothesized that current reconstruction techniques, which are designed mainly to provide resistance to anterior tibial loads, are less effective in limiting knee instability in response to combined rotational loads.

METHODS

Twelve fresh-frozen young human cadaveric knees (from individuals with a mean age [and standard deviation] of 37 +/- 13 years at the time of death) were tested with use of a robotic/universal force-moment sensor testing system. The loading conditions included (1) a 134-N anterior tibial load with the knee at full extension and at 15 degrees, 30 degrees, and 90 degrees of flexion, and (2) a combined rotational load of 10 N-m of valgus torque and 10 N-m of internal tibial torque with the knee at 15 degrees and 30 degrees of flexion. The kinematics of the knees with an intact and a deficient anterior cruciate ligament, as well as the in situ force in the intact anterior cruciate ligament, were determined in response to both loads. Each knee then underwent reconstruction of the anterior cruciate ligament with use of a quadruple semitendinosus-gracilis tendon graft and was tested. A second reconstruction was performed with a bone-patellar tendon-bone graft, and the same knee was tested again. The kinematics of the reconstructed knees and the in situ forces in both grafts were determined.

RESULTS

The results demonstrated that both reconstructions were successful in limiting anterior tibial translation under anterior tibial loads. Furthermore, the mean in situ forces in the grafts under a 134-N anterior tibial load were restored to within 78% to 100% of that in the intact knee. However, in response to a combined rotational load, reconstruction with either of the two grafts was not as effective in reducing anterior tibial translation. This insufficiency was further revealed by the lower in situ forces in the grafts, which ranged from 45% to 65% of that in the intact knee.

CONCLUSIONS

In current reconstruction procedures, the graft is placed close to the central axis of the tibia and femur, which makes it inadequate for resisting rotational loads. Our findings suggest that improved reconstruction procedures that restore the anatomy of the anterior cruciate ligament may be needed.

Anterior cruciate ligament reconstruction with a multistrand hamstring graft fixed with a Ligament Tension Screw: a new device that can be used to readjust graft tension after fixation

We developed a new fixation device for reconstruction of the anterior cruciate ligament with a multistrand hamstring graft. This device allows the graft tension to be readjusted after fixation. This device, called a Ligament Tension Screw, consists of three parts, a screw, a washer, and a post. To create the graft, the tendons were formed into a loop. The device was hung from one end of the loop of the graft and a Kennedy-ligament augmentation device (LAD) artificial ligament was hung at the other end. The Kennedy-LAD artificial ligament was used extraarticularly for fixation at the tibia with double staples. Graft tension was increased by turning the screw, which pulls on the post suspending the graft. Fifty-two patients were evaluated after a minimum 2-year follow-up. The evaluation included physical examination, stability measurement with a KT2000 arthrometer, a Cybex muscle strength measurement, a functional test, and scoring of the knee according to the International Knee Documentation Committee (IKDC). Pivot test was negative in 47 patients (91%), but glide occurred in 5 patients (9%). No patient had a "clunk" or markedly poor result on the pivot test. All patients recovered full extension. Seven patients lost full flexion, but the loss of flexion was less than 5 degree in all seven. The KT 2000 arthrometer measurement with 133 N anterior drawer force indicated that 46 patients (88%) had less than 3-mm side-to-side difference. The mean muscle strength of the quadriceps and hamstrings was 91% and 94%, respectively, compared with the findings in the contralateral limb. The functional test showed a one-leg hop distance equal to 94% of that the opposite side. According to the final IKDC evaluation, 48 patients were graded as normal or nearly normal, and 4 patients as abnormal; none was severely abnormal. This study demonstrated satisfactory results for the reconstruction with a multistrand hamstring graft fixed with the new Ligament Tension Screw.

Reconstruction of the lateral ankle ligaments with bone-patellar tendon graft in patients with chronic ankle instability: a preliminary report

BACKGROUND

Unsatisfactory long-term results have been reported after use of a Broström repair for patients with chronic ankle ligament insufficiency.

HYPOTHESIS

Repair or reconstruction of both the anterior talofibular and calcaneofibular ligaments is essential for normal kinematics of the ankle-hindfoot.

STUDY DESIGN

Case series.

METHODS

Thirteen patients with chronic instability of the ankle were found at operation to have injuries of both the anterior talofibular and calcaneofibular ligaments, with a lack of healthy ligament margins suitable for suturing. Reconstruction of the ligaments was performed with bone-patellar tendon graft. The score devised by Good et al. was used to assess the patients' clinical condition before the operation and at final follow-up.

RESULTS

Before the operation, six patients had a grade 3 clinical condition and seven had a grade 4 condition. At a mean follow-up of 26.5 months, all patients had a grade 1 condition. The average talar tilt of the patients was improved from 18.4 degrees +/- 5.5 degrees to 4.9 degrees +/- 2.6 degrees, and the average anterior drawer sign was improved from 9.1 +/- 2.6 mm to 5.8 +/- 1.6 mm.

CONCLUSION

In cases of combined injuries, short-term results of reconstruction of the anterior talofibular and calcaneofibular ligaments using bone-split patellar tendon graft were good, with a low frequency of complications.

Medial collateral ligament autografts have increased creep response for at least two years and early immobilization makes this worse

Recent evidence has shown that 10-40% of knee joints reconstructed with soft-tissue autografts have a recurrence of abnormal joint laxity over time. One possible explanation is the "stretching out" (or unrecovered creep) of the graft tissue. To test in vitro creep and creep recovery of fresh anatomic ligament autografts in an extra-articular environment, 16 rabbits underwent an orthotopic medial collateral ligament (MCL) autograft procedure to one hindlimb. Three subgroups of animals had either unrestricted cage activity for 1 year (n = 5) or 2 years (n = 5) or pin-immobilization for the first 6 weeks followed by cage activity for the remainder of 1 year (n = 6). Following laxity measurements, to test their creep response, isolated MCL grafts were cyclically and then statically creep tested in vitro at 4.1 MPa, allowed to recover at zero load for 20 min, and finally elongated to failure. Due to differences in cross-sectional area between the grafts and normal MCLs, two normal control groups were tested: stress-matched tested at 4.1 MPa (16.2 N; n = 7) and force-matched tested at 29.1 N (7.1 MPa; n = 6). Ligament grafts had normal laxity but significantly increased creep and decreased creep recovery compared to normal MCLs after I and 2 years of healing (p < 0.0004). Graft failure stress was also significantly less than normal (p < 0.0001). Immobilized grafts had significantly greater creep compared to non-immobilized grafts at 1 year of healing (p < 0.05). These results support previous observations concerning material inferiority of fresh anatomic rabbit MCL autografts, but add the concept that such grafts also have increased potential to creep with either slower or incomplete recovery when subjected to low stresses in vitro. Joint and ligament laxities in situ were normal in this model, however, suggesting either that in vivo MCL graft stresses are lower than those used here in vitro or that these tissues have other mechanisms by which they can recover their functional length in vivo.

A multidisciplinary study of the healing of an intraarticular anterior cruciate ligament graft in a goat model

We evaluated knee function, tensile properties, and histologic appearance of a healing intraarticular bone-patellar tendon-bone autograft after anterior cruciate ligament reconstruction in a goat model. The patellar tendon graft was fixed such that both bone-to-bone (femoral tunnel) and bone-to-tendon (tibial tunnel) healing could be studied. The total anteroposterior translation significantly increased from 3 to 6 weeks, ranging from increases of 28.8% to 46.7%. In situ forces in the replacement graft decreased as much as 22.2% at 6 weeks. Conversely, tensile properties of the femur-anterior cruciate ligament graft-tibia complex did not change significantly from 3 to 6 weeks. However, the mode of failure changed from the graft pulling out of the tibial tunnel at 3 weeks to a mix of midsubstance failures (N = 2) and pullouts (N = 5) at 6 weeks. Histologic evaluations revealed progressive and complete incorporation of the bone block in the femoral tunnel, but only partial incorporation of the tendinous part of the graft in the tibial tunnel. The differences demonstrated at 3 and 6 weeks may be a result of the remodeling process of the midsubstance of the graft as the interfaces within the osseous tunnels mature.

Bone tunnel remodeling at the site of biodegradable interference screws used for anterior cruciate ligament reconstruction: 5-year follow-up

PURPOSE

The purpose of this prospective study was to review, using expanded clinical-assessment tools, the long-term results of the local effects of a bioabsorbable interference screw (copolymer 85/15 D,L lactide/glycolide) in anterior cruciate ligament (ACL) reconstruction.

TYPE OF STUDY

This prospective study was initiated in May 1993. The inclusion criteria for patient selection included rupture of the ACL in athletic patients without involvement of the collateral ligaments, arthroscopic ACL reconstruction using middle third of the ligamentum patella, and magnetic resonance imaging (MRI) and plain radiographic examinations of the knee joint during follow-up.

MATERIALS

Between May 1993 and October 1994, 32 patients were enlisted in the study; 48 patients did not fit the inclusion criteria. There were 25 men 7 women. The average age was 29.1 years (range, 19 to 50 years). There were 21 right knees and 11 left knees. The follow-up examinations were performed by an independent examiner. There were 28 patients available for follow-up at a medium of 5.2 years (range, 4.1 to 6.4 years). The evaluation included various testing systems (i.e., OAK, IKDC, Lysholm) as well as MRI and plain radiographic studies to investigate the longevity of the implant and potential adverse effects of this new bioabsorbable material.

RESULTS

The clinical results were good. The OAK score (Orthopädische Arbeitsgruppe Knie) showed 93% excellent and good results, and 7% fair results. The IKDC and Lysholm scores were 92% and 96% good and excellent results, respectively. MRI showed bone remodeling and new bone formations at the site of the implant in the femoral as well as in the tibial bone tunnel at follow-up. No cystic or osteolytic changes where seen on MRI or plain radiographs.

CONCLUSIONS

This study showed the correlation between histology and MRI: there was minimal surgical-site edema, minimal reaction to this material, and complete replacement by new bone formation of the previous site of this implant. At 5 years, this bioabsorbable interference screw appeared clinically safe and effective for fixation of bone blocks during ACL reconstruction and MRI showed complete absorption and replacement with new bone.

Anterior cruciate ligament reconstruction. A prospective randomized study of three surgical methods

A prospective randomized study was performed to determine the differences in results between three methods of anterior cruciate ligament reconstruction: autogenous bone-patellar tendon-bone graft (group 1), semitendinosus and gracilis tendon graft reconstruction combined with an extraarticular procedure (group 2), and semitendinosus and gracilis tendon graft reconstruction alone (group 3). Preoperatively, there were no significant differences between groups. At a mean of 35.4 +/- 11.6 months postoperatively, 102 patients returned for evaluation. International Knee Documentation Committee knee evaluation revealed no significant differences in symptoms, function, return to pre-injury activity, harvest site abnormalities, or limitation of motion between groups 1 and 3. Patients in group 2 had a higher incidence of patellofemoral crepitation and loss of motion than did patients in group 3. The mean manual maximum KT-1000 arthrometer side-to-side difference was 2.1 +/- 2.0 mm in group 1, which was statistically significantly better than the difference in group 3 (3.1 +/- 2.3 mm). Final knee rating showed that 34 of 35 patients in group 1, 23 of 34 patients in group 2, and 26 of 33 patients in group 3 had a normal or nearly normal overall knee rating. Anterior cruciate ligament reconstruction with a semitendinosus and gracilis or a patellar tendon autograft may yield similar subjective results; however, the patellar tendon autograft may provide better objective stability in the long term. In addition, there appears to be no benefit to combining an intraarticular anterior cruciate ligament reconstruction with an extraarticular procedure.

Alteration of patellofemoral contact during healing of canine patellar tendon after removal of its central third

Alterations of the patellofemoral (PF) contact pressure and area were assessed using pressure-sensitive film after the removal of the central third of patellar tendon (PT) with healing over time in twelve dogs. The contralateral knee served as control. Histological sections were prepared for descriptive evaluation. No alterations in PT strain, PF contact pressure and area were measured immediately after the removal of the central third of PT compared with that before its removal. Compared with contralateral control, the healing of the donor PF induced a significantly increased PF contact area but not PF contact pressure in the specimens harvested at 6, 12, and 18 months after operation. Increased PF contact area indicated a proximal shift of the PF joint contact during flexion, which was associated with an increased strain of the healing PT under loading. The healing PT became hypertrophic compared with control, but the differences in the cross-sectional area were reduced over time. Histologically, a poorly organized extracellular matrix was observed at 6 months, with a progressive improvement in collagen fiber alignment up to 18 months postoperatively. The results of this study suggest that the removal of the central third of PT does not immediately change PF contact pressure and areas. However, remodeling of the healing tendon may cause an elongated PT, resulting in an increase in PF contact area under a given quadriceps force by knee extension.

Long-term results of anterior cruciate ligament reconstruction using ilio-tibial tract and semitendinosis tendon

During the 3-year period from June 1984 to July 1987, 115 anterior cruciate ligament reconstructions were performed by a combined intra- and extra-articular technique using the anterior three-quarters of the ilio-tibial band and the semitendinosis tendon. Post-operative rehabilitation included limited mobilization in flexion for 6 weeks post-surgery. Eighty-four knees (78% follow-up) were reviewed at a mean of 8 years (range 6.3-9.7 years). The long-term results of surgery were assessed using the Lysholm score, Noyes activity rating, the International Knee Documentation Committee (IKDC) knee ligament standard evaluation and manual maximum KT-1000 side-to-side difference measurements were made. In addition 45 knees were examined radiographically. Reconstruction within 6 weeks of injury led to a significantly higher chance of concurrent meniscal trauma being suitable for repair (P=0.002). At early reconstruction coincidental macroscopic chondral damage was noted in 23% and limited to the patella while at delayed reconstruction 45% of knees showed chondral damage which also involved tibio-femoral compartments in some cases. Overall 87% returned to their pre-injury sporting level and only one ceased through knee problems. Ninety-three percent had a manual maximum KT-1000 side-to-side difference at final review no greater than 3 mm. The Lysholm score rated results as 91% excellent or good while the overall IKDC evaluated 85% as normal or near normal, 14% abnormal and 1% (one case) as severely abnormal. Twenty-seven percent of acute and 10% of delayed reconstructions developed some degree of arthrofibrosis (P=0.049) and this significantly predisposed the knee to early degenerative change (P=0.002).

Femoral tunnel position in anterior cruciate ligament reconstruction using three techniques. A cadaver study

The possibility of achieving correct deep femoral tunnel positioning during anterior cruciate ligament (ACL) reconstruction with the double incision technique (DI), the transtibial technique (TT), and the anteromedial technique (AM) was evaluated in 30 cadaver knees. A reference hole was made just deep to the insertion of the anteromedial bundle of the ACL through an anteromedial arthrotomy. In the DI technique, a Kirshner wire was inserted outside-in using a rear entry C guide. In the TT and AM techniques, the K-wire was inserted inside-out through the tibial tunnel and through the arthrotomy, respectively. The reference hole could be achieved with each technique. Using lateral radiographs, the superficial aspect of the intra-articular exit of the femoral tunnel was found to be located on average at 36%, 36%, and 34% of the width of the condyles from the posterior margin (NS). None of the holes was more anterior than 40%. In conclusion, a deep femoral tunnel positioning could be achieved with each technique. The choice of technique must be based on the surgeon's preference and clinical results.

Bioabsorbable interference screws for graft fixation in anterior cruciate ligament reconstruction

The central one third of the patellar tendon autograft is popular because the bone-tendon-bone (BTB) construct provides several graft fixation options, robust graft incorporation, and a mechanically sufficient substitute. Interference screw fixation is one method used to secure the graft. Bioabsorbable interference screws may offer advantages over metal interference screws. Bioabsorbable screws are made from poly L-lactic acid (PLLA) and are absorbed by the body. This prospective, randomized study compared the safety and efficacy of the PLLA screw with that of the metal cannulated interference screw for anterior cruciate ligament reconstruction. There were 204 patients randomly assigned to the Bioscrew (Linvatec, Largo, FL) (n = 103) or the metal interference screw (n = 101) groups at four sites. The mean age was 30 years. There were 66 women and 138 men. Mean follow-up was 30 months for Bioscrews and 28 months for metal screws; the average follow-up interval was 2.4 years. The Lysholm mean scores at 4 years for the 32 patients seen at this interval were 95.0 and 97.2 for the Bioscrew and metal screw group, respectively. Ligament laxity comparisons made with an instrumented arthrometer at manual maximum force resulted in side-to-side mean score differences of B = 1.8mm and M = 1.6mm. The Tegner activity level score means were B = 6.1 and M = 5.8. Other variables examined included pain, thigh size, meniscal tests, Lachman's test, range of motion, anterior drawer, pivot shift, patellofemoral crepitus and tenderness, and joint effusion. None of these variables showed a statistically significant difference between groups. No radiographic evidence of osteolytic change or bone resorption around the Bioscrews was observed. There were no complications related to loss of fixation, toxicity, allergenicity, or other evidence of osteolytic or inflammatory reaction. In every assessment between groups there was no difference found. There were 12 PLLA screws that broke during insertion without any adverse effects. The PLLA headless cannulated interference fit screws produce equal results to similarly designed metal screws.

Serial magnetic resonance imaging evaluation of a bioabsorbable interference screw and the adjacent bone

The purpose of this prospective study was to review, using expanded clinical assessment tools, the initial use of a bioabsorbable interference screw (copolymer 85/15 D, L lactide/glycolide) in anterior cruciate ligament (ACL) reconstruction at the Wels Hospital, Austria. The study enlisted 32 patients of whom 28 were available for follow-up at minimum of 2.5 years. Since the implant material was new and the screw would not show on plain film radiographs, the clinical assessment was expanded beyond the usual historical and physical findings. The evaluation included opportunistic knee joint aspiration and repeat magnetic resonance imaging (MRI) studies to investigate the longevity of the implant and potential adverse effects of this new bioabsorbable material. The knee joint aspirations showed no infection. Serial MRIs showed the physical presence of the screw to remain intact for 4 months and disappear in 6 months. The MRIs showed minimal collection of edema around the bone tunnels that resolved by 12 months. There were no symptoms or adverse clinical result correlated with the MRI evidence of edema. There was temporary bone tunnel expansion. The clinical results were good. The OAK-score (Orthopädische Arbeitsgruppe Knie) showed 89.5% excellent and good results, 7% fair results and 3.5% poor results. The average score was 90.7 points (range, 63 to 100 points). The knee joint stability measured with the KT-1000 arthrometer showed 93% to have a 3-mm or less difference compared with the unoperated knee. This bioabsorbable interference screw appeared safe and effective for fixation of bone blocks during ACL reconstruction while producing no occult infection or adverse clinical response during the degradation process.

Strain rate effect on the mechanical behavior of the anterior cruciate ligament-bone complex

Traction tests were performed on the bovine anterior cruciate ligament-bone complex at seven strain rates (0.1, 1, 5, 10, 20, 30, 40%/s). Corresponding stress-strain curves showed that, for a given strain level, the stress increased with the augmentation of the strain rate. This phenomenon was important since the stress increased by a factor of three between the tests performed at the lowest and highest strain rates. The influence of the strain rate was quantified with a new variable called the "supplemental stress". This variable represented the percentage of total stress due to the effect of strain rate. It was observed that at a strain rate of 40%/s, more than 70% of the stress in the ligament was due to the strain rate effect. In fact, the strain rate strongly affected the toe region, but did not influence the linear part of the stress-strain curves. The use of the linear tangent moduli was then not adequate to describe the strain rate effect in the anterior cruciate ligament-bone complex. This study showed that the "supplemental stress" was a synthetic and convenient variable to quantify the effect of the strain rate on the entire stress-strain curves. This quantification is especially important when comparing the mechanical behavior between anterior cruciate ligament and tissues used as ligament graft.

Effects of patellar tendon adhesion to the anterior tibia on knee mechanics

The effects of patellar tendon adhesion on the knee extensor mechanism and on the kinematics and contact areas for both the patellofemoral and tibiofemoral joints were determined for five cadaveric knees in an open kinetic chain testing configuration. Patellar tendon adhesion decreased the distance from the inferior patellar pole to the tibial tuberosity, effectively creating patella infera. When compared with the controls, knees with adhesion had medial and distal translation of the patella, as well as increased patellar flexion. Although the patellar articular contact location shifted distally, the overall contact area did not change significantly. For the tibia, adhesion resulted in significant medial, proximal, and anterior translation, and internal rotation. Adhesion also resulted in a posterior shift of the tibial contact location. For the extensor mechanism, adhesion decreased the knee extension force created by the quadriceps muscle on the tibia, indicating a decrease in the effective moment arm of the extensor mechanism. Furthermore, as a result of patellar tendon adhesion, the angle formed by the quadriceps and patellar tendons decreased, suggesting an increase in patellofemoral joint reaction force with adhesion. The increased patellofemoral joint reaction force and the altered contact location may be related to anterior knee pain after knee trauma and knee surgery. Therefore, patients should be observed for subtle patella infera, which may indicate patellar tendon adhesion.

Refixation of femoral anterior cruciate ligament tears combined with a semitendinosus tendon augmentation. Technique and results

As part of a retrospective study, 76 patients with acute tears of the anterior cruciate ligament who underwent reinsertion and augmentation with the semitendinosus tendon were examined. The follow-up took place on average 4.5 years (range 3-7 years) after surgery. A decreased range of motion upon comparison with the uninjured opposite side was seen in 43 patients. The Lachman test revealed a grade 1 instability in 42 patients, grade 2 in 17 and grade 3 in 2, while 15 patients had a negative test result. The average Lysholm score was 92 points and the Tegner activity score had an average of 7.1 points. KT-1000 measurements showed an identical degree of anterior translation for both knees at 89 N in 25 individuals. The analysis revealed a difference of 2 mm in 15 patients, 4 mm in 19,6 mm in 15 and greater than 6 mm in 2. The radiographic follow-up examination revealed a deterioration of the degenerative change of 1 deg in 17 patients and 2 deg in 4 patients. Isometric testing showed no loss in flexion strength of the operated knee joints compared to the healthy opposite side. The ratio between flexion and extension strength was also identical for both knees. The reinsertion and augmentation with a single strand of semi-tendinosus tendon is not, as this study demonstrates, the appropriate reconstructive technique for the majority of ACL tears.

Single-incision endoscopic anterior cruciate ligament reconstruction using patellar tendon autograft. Minimum two-year follow-up evaluation

We conducted a retrospective, minimum 2-year follow-up study to evaluate the effectiveness of a single-incision endoscopic anterior cruciate ligament reconstruction technique using patellar tendon autograft without extraarticular augmentation and followed by accelerated rehabilitation. One hundred three patients were evaluated (mean followup, 36 months; range, 24 to 55). There were significant improvements in physical examination test results (Lachman, anterior drawer, and pivot shift) postoperatively, and 94 patients (91%) had negative pivot shift results. KT-1000 arthrometric testing showed a significant reduction in manual maximum anterior translation and side-to-side differences at followup. Good range of motion was achieved. Patients with asymmetric prone heel heights usually had hyperextension in the contralateral knee. Functional tests showed 4% to 6% differences in side-to-side comparisons for a timed single-legged hop, single-legged hop for distance, and vertical jump. Postoperatively, the results of the Tegner scale were similar to preinjury scores. The mean results of the Hospital for Special Surgery scale (90), Lysholm score (89), and Noyes sport function score (90) were all excellent or good. Only 5 patients (5%) required reoperations for flexion contractures. Ninety-six patients (93%) reported they were "mostly" or "completely" satisfied, and 98 (95%) would recommend the procedure to others. These results demonstrated encouraging outcome using this single-incision technique.

Thigh muscle size and strength after anterior cruciate ligament reconstruction and rehabilitation

It is the hypothesis of the senior author (GAA) that high circumference measurements are not an accurate reflection of thigh muscle cross-sectional area or muscle strength after standard rehabilitation following anterior cruciate ligament reconstruction. Likewise, normal quadriceps femoris strength is not achieved in these patients despite aggressive rehabilitation. The purpose of our study was to quantify thigh muscle size and strength and correlate thigh circumference, muscle cross-sectional area by magnetic resonance imaging (MRI), and isokinetic strength in our patients. Thirty-three patients with anterior cruciate ligament repair utilizing autografts of iliotibial band (N = 28), semitendinosus autograft (N = 3), and bone-patellar tendon-bone autograft (N = 2) were retrospectively evaluated 48.7 +/- 6.91 months after surgery. We compared involved operated extremities with uninjured, uninvolved contralateral extremities, measuring thigh circumference, isokinetic peak torque, and cross-sectional area by MRI. We found a significant 1.8% decrease in thigh circumference, a 10% decrease in average quadriceps torque, and a 8.6% decrease in quadriceps cross-sectional area by MRI in the involved extremities compared with the uninvolved extremities. A positive correlation between MRI cross-sectional area, quadriceps, and hamstring peak torque was recorded in involved and uninvolved extremities. A positive correlation between thigh circumference, quadriceps, and hamstring peak torque was found in uninvolved extremities but not in operated extremities. The authors concluded that thigh circumference underestimates atrophy and is not correlated with cross-sectional thigh muscle area by MRI or strength in operated extremities. Persistent quadriceps weakness and decreased cross-sectional area at 49 months postsurgery and rehabilitation continue to challenge our efforts. The pathophysiology of the decrease in thigh muscle size and quadriceps femoris strength is discussed.

Anterior cruciate ligament reconstruction with autogenous patellar tendon graft in patients with articular cartilage damage

To test if anterior cruciate ligament reconstruction with autogenous patellar tendon can alleviate symptoms and functional limitations and increase activity levels in patients with advanced articular cartilage damage, we looked at 53 patients with arthroscopically documented cartilage damage. In this group, a mean of 7.5 years had elapsed between the original injury and the reconstruction, and 90 prior operative procedures had been done. Postoperatively, all patients had immediate motion and early functional rehabilitation. The results were assessed with the Cincinnati Knee Rating System. At followup (mean, 27 months), significant improvements were found for pain, swelling, giving way, functional limitations with daily and sports activities, and the overall rating score. Forty-two patients (79%) had returned to some type of athletic activity. Only three patients (6%) had failed results. In the patients' own ratings of the overall knee condition, 8 of 51 (16%) rated their knees as normal, 28 (55%) as very good, 7 (14%) as good, 5 (10%) as fair, and 3 (6%) as poor. We concluded that the majority of patients benefited from the arthroscopically assisted anterior cruciate ligament reconstruction because it decreased episodes of giving way with daily activities and increased activity without aggravating the preexisting arthrosis.

A rigorous comparison between the sexes of results and complications after anterior cruciate ligament reconstruction

Although there is a higher relative incidence of anterior cruciate ligament injuries in female than in comparable male athletes according to the literature, the majority of populations studied after reconstruction are male-dominated. We wished to determine whether a selection bias for reconstruction based on sex is warranted according to complications and outcome. Ninety-four patients (47 of each sex) were matched for chronicity of injury, age, preoperative sports activity levels, articular cartilage condition, and months of followup. All had patellar tendon autogenous reconstruction and a similar program of immediate knee motion and early return to function. The results were rated with the Cincinnati Knee Rating System. At a mean of 26 months postoperatively, there were no significant differences for complications or outcome between men and women. Women required an average of six more rehabilitation visits than men; however, none required additional surgery for knee motion complications and the rate of patellofemoral crepitus conversion was only 7%, lower than that found for men (15%). The overall failure rate was low, only 6% for women and 4% for men. We concluded that the functional rehabilitation program was effective, postoperative complications were few, and no scientific basis exists to use sex alone as a selection criteria for anterior cruciate ligament reconstruction.

A comparison of results in acute and chronic anterior cruciate ligament ruptures of arthroscopically assisted autogenous patellar tendon reconstruction

We conducted a prospective study of 94 consecutive patients who received a patellar tendon autograft for anterior cruciate ligament rupture. Eighty-seven patients (93%) returned for followup a mean of 28 months postoperatively; 57 had chronic and 30 had acute or subacute ruptures. There were no significant differences between the subgroups for age, sex, articular cartilage lesions, or months of followup. Forty-six meniscal tears were repaired; 27 of these extended into the central avascular region. Rehabilitation emphasized immediate knee motion, but strenuous activity was delayed for at least 4 months. Only one patient had a knee motion complication, and stability (<3 mm, KT-2000 arthrometer, 134 N) was restored in 85% of knees with chronic ruptures and 92% of knees with acute ruptures. Earlier reconstruction should be considered in active persons as symptoms and limitations continued postoperatively in knees with chronic ruptures, leading to overall less satisfactory results. In patient rating of the overall knee condition, 69% of knees with chronic ruptures and 100% of knees with acute ruptures scored in the normal or very good range. Repair of meniscal tears that extend into the central avascular region should be considered, as 24 of the 27 (89%) menisci repaired showed clinical evidence of healing and did not require reoperation.

Long-term results of anterior cruciate ligament reconstruction with a Dacron prosthesis. The frequency of osteoarthritis after seven to eleven years

In this prospective study we investigated 70 patients with chronic anterior instability who underwent anterior cruciate ligament reconstruction with a Dacron prosthesis. Fifty-five (79%) patients could be followed up at a mean of 9 years. Within the follow-up time, 44% (29 of 66) of the prostheses were diagnosed as ruptured; the annual rupture frequency was 5%. Second reconstructions were performed for 20 patients (29%), 5 patients had third reconstructions, and 9 patients wanted no further surgical treatment. Fifty-two patients (74% of the original group) underwent radiographic examination. Eighty-three percent (43) of these patients had radiographic changes in the operated knee, and 40% (21 of 52) had joint space reduction up to 50%. The rate of radiographically detected osteoarthritis was increased 10 times compared with the normal knee. Patients with medical instability and patients older than 30 years at the initial operation had more severe osteoarthritic changes. Based on the functional results of the patients with a ligament in place after 9 years, only 14% (10) of the original group had acceptable stability and knee function.

Arthroscopic-assisted allograft anterior cruciate ligament reconstruction in patients with symptomatic arthrosis

We reviewed the results of arthroscopic-assisted anterior cruciate ligament (ACL) allograft reconstruction in 40 patients who had advanced articular cartilage deterioration documented by arthroscopy during the reconstruction. A mean of 7 years had elapsed between the original injury and the reconstruction, and 102 prior operative procedures had been done in 34 of the 40 patients. A total of 64 articular cartilage lesions were noted; 34 knees had lesions in the medial or lateral tibiofemoral compartment. Postoperatively, all had immediate motion and early functional rehabilitation. The results were assessed using the Cincinnati Knee Rating System. At follow-up (mean, 37 months), significant improvements were found for pain, giving-way, and functional limitations with daily and sports activities (P < .01). Fifty-five percent had returned to mostly light athletics (avoiding high impact sports) based on our advice and were asymptomatic. The mean overall rating scores significantly improved (P < .0001, mean improvement 22 points). We concluded that the majority of patients in this study with chronic ACL rupture and post-traumatic arthrosis benefited short-term from arthroscopic-assisted ACL reconstruction.

Is an anterior cruciate ligament reconstruction outcome age dependent?

Treatment of a torn anterior cruciate ligament (ACL) in older patients must be considered in relation to healing delays, rehabilitation difficulties, stiffness, arthritis, and actual athletic demands. This study compares ACL reconstructions in patients 40-years old and older with those under 40-years old and contrasts these to published nonoperative data in the 40 and older patient. Patients undergoing ACL reconstruction between 1992 and 1994 were preoperatively and postoperatively assessed with Lysholm, Tegner, KT, radiographic, and clinical examinations. They were divided into two groups: those 40 years and older (group 1) and those 39 years and younger (group 2). Group 1 had 33 patients with an average age of 44 years (range, 40 to 52 years). Radiographic Fairbank changes were absent. Group 2 had 170 patients with an average age of 27 years (range, 16 to 39 years). Group 1 preoperative instability and intake data were not statistically different from those of group 2. Average follow-up was 21 months for both groups. Both groups showed significant improvement in all parameters at 12- and 24-month follow-up examinations. Lysholm scores, Tegner scores, average KT manual maximum side-to-side differences, Lachman tests, and pivot shift testing were not statistically different in either group. Using Lysholm criteria, in group 1, 89% had excellent/good results, and 11% fair/poor results. This was not statistically different from group 2, which showed 91% excellent/good results and 9% fair/poor results at 24-month follow-up examination. For this age group, nonoperative treatment reports indicate 57% excellent/good results and 43% fair/poor results. The outcomes between these groups are the same and fail to establish the age of 40 years as a barrier to successful ACL reconstruction.

Arthroscopically assisted semitendinosus and gracilis tendon graft in reconstruction for acute anterior cruciate ligament injuries in athletes

We evaluated 69 arthroscopically assisted anterior cruciate ligament reconstructions for acute tears at an average followup of 60 months. We used a distally based single semitendinosus and gracilis tendon graft passed over the top and fixed to the femur. Combined medial collateral ligament lesions were seen in 30 knees, and they were repaired when found in the distal third (18 knees). The patients were instructed to recover motion preoperatively, and an early range of motion program was used postoperatively. At followup, symptoms of giving way were seen in five knees (7%). Graft failure was seen in seven knees (10%); failure was defined as a positive pivot shift (clunk or gross) or a side-to-side difference in anterior tibial displacement greater than 5 mm, as measured with a KT-1000 arthrometer. Permanent extension loss (3 degrees to 5 degrees) was found in two knees (3%). Patellofemoral crepitation was seen in eight knees (12%), but the condition was symptomatic in only one knee. Forty-six patients (67%) were active in pivoting sports before surgery and 37 (54%) remained active in these sports at followup. We concluded that this operation is simple, effective, and has a low complication rate. Further studies are necessary to elucidate if a stronger graft (e.g., a patellar tendon) would decrease the rate of graft failure without increasing complications.

Anterior cruciate ligament reconstruction in athletes with an ossicle associated with Osgood-Schlatter's disease

We report a series of 20 athletes with an ossicle associated with Osgood-Schlatter's disease (OSD) who underwent anterior cruciate ligament (ACL) reconstruction using autogenous, central-10-mm patellar-tendon graft. All patients had an Osgood Schlatter's lesion with an ossicle as seen on a plain radiograph. The patients were reviewed at an average follow-up of 44 months (range, 24 to 108 months). The postoperative assessment included clinical examination, KT-1000 testing, isokinetic testing, and subjective score (using the modified Noyes' questionnaire). At the time of latest review, all 20 patients had a stable knee. The average side-to-side difference on manual maximum KT-1000 assessment was 1.9 mm (range, 0 to 5 mm). Average time to return to full sporting activities was 5.2 months (range, 2.6 to 8.9 months). All patients returned to their previous level of activity. The mean modified Noyes' knee score was 96 (range, 89 to 100). To date, no graft failure has occurred. Based on the results of this study, we believe that ACL reconstruction using the autogenous bone-patellar tendon-bone graft can be safely undertaken in athletes with an ossicle associated with OSD without compromising the final knee function.

Single versus two-incision arthroscopic anterior cruciate ligament reconstruction

The purpose of this study was to compare single (endoscopic) versus two-incision arthroscopic anterior cruciate ligament reconstruction using bone-patellar tendon-bone in a population of young athletes. All patients followed a similar postoperative rehabilitation program. The Lysholm knee score, the International Knee Documentation Committee Score, KT-1000 arthrometric measurements, Lachman tests, pivot shift tests, isokinetic and functional testing, and perioperative complications were used to compare the two techniques. Anteroposterior and lateral radiographs were also evaluated and compared. Group I comprised 51 patients who underwent two-incision arthroscopic ACL reconstruction. The average age was 19.8 years, with a range of 18 to 22. The average follow-up in this group was 31 months (range, 24 to 43 months). Group II, the endoscopic group, consisted of 31 patients with an average age of 19.4 years (range, 18 to 22). The average follow-up was 25 months (range, 24 to 31 months). There were no significant differences between the two groups using subjective, objective, and functional criteria. There did appear to be a trend toward a residual pivot glide in the endoscopic group, but this did not achieve statistical significance. Radiographic analysis demonstrated an increased incidence of screw divergence in the endoscopic group. Intraoperative complications were more common with the endoscopic method.

Brace-free rehabilitation, with early return to activity, for knees reconstructed with a double-looped semitendinosus and gracilis graft

Forty-one patients in whom operative reconstruction of a torn anterior cruciate ligament had been performed by one surgeon with use of a double-looped semitendinosus and gracilis hamstring graft were studied to determine (1) if a brace-free rehabilitation program compromised the early stability of the knee; (2) if the stability of the knee deteriorated between four months, when the patient returned to unrestricted activities, and two years; and (3) if the function of the treated knee was completely restored by four months after the operation. The graft was placed arthroscopically, without impingement by the intercondylar roof, and was fixed within the tibial tunnel to conserve the length of the graft. The stability and function of thirty-seven of the knees were assessed at four months as part of a larger prospective study. Four patients chose not to return for the four-month evaluation. The patients returned to unrestricted sports and work activities after the four-month evaluation. At two years, all forty-one patients were evaluated. At four months, after completion of the brace-free rehabilitation program, thirty-three (82 per cent) of the thirty-seven patients had an absent pivot shift and a normal Lachman test. Twenty-eight (88 per cent) of thirty-four knees had less than three millimeters of difference in laxity compared with the contralateral knee, as determined by testing at the maximum manual force with use of a KT-1000 arthrometer. Stability remained unchanged at two years, justifying the early return to vigorous activities at four months. The girth of the thigh, the extension of the knee, and the Lysholm and Gillquist score were the same at four months as at two years, verifying the success of the brace-free intensive rehabilitation program in the restoration of early function to the treated knee. However, some continued improvement was observed in the performance of the one-leg-hop for distance test between four months and two years.

Revision anterior cruciate ligament surgery: experience from Cincinnati

Prospective studies were done to determine the outcome of allografts and autografts used for revision anterior cruciate ligament reconstruction. The allograft group was comprised of 65 patients observed for a mean of 42 months postoperatively; the autograft (bone-patellar ligament-bone) group contained 20 patients observed for a mean of 27 months postoperatively. KT-2000 testing and a comprehensive knee examination were done on all the patients. The Cincinnati Knee Rating System was used for assessment. Significant improvements were noted in all patients for symptoms, functional limitations, anteroposterior displacements, pivot shift tests, and overall rating scores. KT-2000 results showed 53% of the allograft group and 67% of the autograft group had less than 3 mm increased displacement (not statistically significant). The overall failure rates were 33% for the allografts and 27% for the autografts. Preoperative planning and technical aspects of anterior cruciate ligament revision procedures are described. The authors prefer bone-patellar ligament-bone autografts for anterior cruciate ligament revision, although the data presented were considered preliminary. Bone-patellar ligament-bone allografts may be used when autogenous tissues are not available, because they offer reasonable success rates for patients who are symptomatic with daily activities.

The tendon defect after anterior cruciate ligament reconstruction using the midthird patellar tendon--a problem for the patellofemoral joint?

Retrospective clinical and radiographic evaluation was performed on 41 patients seen at the Salzburg General Hospital Department of Traumatology on average 2 years following ACL reconstruction. In 26 patients (61%) clinical examination revealed pain trigger points over the donor site of the midthird patellar tendon and in the patellofemoral joint. Functional pain during kneeling activities was observed in 19 patients (46%). Objective measurement of the length of the patellar tendon in bilateral radiographs demonstrated exactly equal patellar tendon length in both knees in 11 patients (27%). The radiographs showed tendon shortening following harvesting of the midthird patellar tendon by 1-3 mm in 7 patients (17%), by 4-6 mm in 16 (39%), and by 6-9 mm in 7 (17%). Average length change in the patellar tendon on the donor side was -3 mm, representing a patellar tendon shortening of 9.8%. On the basis of the OAK score, however, good and very good results were recorded in 33 patients (80%). On the whole, these good overall results were compromised only be patellar tendon defect morbidity. In addition to the local scarring problems at the donor site, shortening of the patellar tendon was observed with changes to patella position and interference with the mechanics of the patellofemoral joint. Tendon shortening can be explained on the basis of cicatricial contraction in the process of autorepair to the tendon defect. The problems affecting the patellofemoral joint are inherent in the therapy and must be treated as a negative factor. In the case of patients whose work requires mainly a kneeling position and those who make significant functional demands of the extension system of the knee, a critical assessment is required of the use of the midthird patellar tendon for anterior cruciate ligament reconstruction.