Prosthetic Ligament Research Articles

Revision Anterior Cruciate Ligament Reconstruction with Doubled Semitendinosus and Gracilis Tendons and Lateral Extra-Articular Reconstruction

The outcome of revision anterior cruciate ligament reconstruction has only rarely been reported. The purpose of this study was to evaluate the results of revision anterior cruciate ligament surgery with use of an autogenous doubled semitendinosus and gracilis graft in association with an extra-articular procedure. Between 1997 and 2003, thirty patients underwent a repeat reconstruction of a previously reconstructed torn anterior cruciate ligament with use of a doubled semitendinosus and gracilis graft combined with an extra-articular reconstruction. Primary reconstruction had been done with an autogenous patellar tendon graft in twenty-six patients and with a prosthetic ligament in four patients; the average time from the primary reconstruction to the revision was five years. Functional outcomes, graft survival, and radiographic outcomes were evaluated at a mean of five years. A graft was considered to have failed when a revision was done or when the side-to-side difference on KT-1000 arthrometer testing was >5 mm and/or the pivot-shift test grade was greater than a trace. One patient underwent another revision reconstruction because of graft failure at three years postoperatively. The mean International Knee Documentation Committee (IKDC) subjective knee score for the remaining twenty-nine patients was 84 +/- 12 points, and the mean Lysholm knee score was 90 +/- 10 points. The side-to-side difference as measured with the KT-1000 arthrometer with maximum manual force was <3 mm in twenty patients (of the twenty-eight who returned for follow-up), between 3 and 5 mm in six patients, and >5 mm in two patients. The result of the pivot shift examination was normal in fifteen patients, slightly positive in eleven patients, and positive in two patients. Twenty-five percent of the patients showed no radiographic signs of degenerative joint disease. Revision anterior cruciate ligament reconstruction with use of an autogenous doubled semitendinosus and gracilis graft combined with an extra-articular procedure provided satisfactory functional outcomes, with a failure rate of 10%.

Fourteen-Year Prospective Results of a High-Density Polyethylene Prosthetic Anterior Cruciate Ligament Reconstruction

Our experience with an ultrahigh molecular weight polyethylene (UHMWPE) braided graft indicates that this prosthetic anterior cruciate ligament (ACL) is not associated with the complications of other prosthetic ligaments and has equivalent results compared to an autograft. Nine patients underwent ACL reconstruction with the UHMWPE prosthetic graft, and seven patients received a bone-patellar-bone autograft. Each patient completed a questionnaire regarding their symptoms, a Tegner score, and a Lysholm Score. Objective results included a physical examination and KT1000 measurement. Noninferiority statistical methods were utilized to calculate a power to detect a clinically relevant difference between the groups. Six individuals from the prosthetic group and six of the controls have been followed an average of 14.1 years. In the prosthetic group, one graft failed at 9.5 years after the reconstruction. There were no sterile effusions. There were no graft failures or sterile effusions in the controls. Tegner scores were equivalent (control = 5.5, prosthetic = 5.0) as were the Lysholm scores (control = 82, prosthetic = 80.5). KT1000 testing for the prosthetic group (mean side-to-side difference in maximal displacement = 1.75 mm) was not inferior to the control group (2.0 mm). In this prospective study with 14 years of follow-up, the subjective and objective results of a prosthetic ACL compares favorably to an autograft, suggesting reconsideration of a prosthetic graft options as a viable option.

Long-Term Clinical Review (10-20 Years) after Reconstruction of the Anterior Cruciate Ligament Using the Leeds-Keio Synthetic Ligament

Prosthetic ligament use for anterior cruciate ligament (ACL) reconstruction was popular in the 1980s and 1990s. Information from published studies regarding the long-term outcomes of this surgery is limited. This paper presents the long-term results of stabilization of the ACL deficient knee using the Leeds-Keio synthetic ligament formed from woven polyester. Fifty patients were seen in clinic at a mean follow-up of 11.9 years (range 8.7-19.7 years). The mean ages were: at injury 26.8 years (range 16-47 years), at surgery 29.9 years (range 18-47 years), and at review 42 years (30-56 years). Of the 50 patients included, 86% were male and 14% were female. The main causes of injury were football (42%), rugby (25%), and skiing (8%). The mean time from injury to surgery was 37.6 months (range 0-324 months). All patients received intra-articular (IA) ligaments placed in the anatomical position of the natural ACL. In addition, approximately 75% also had an extra-articular ligament placed so that it ran parallel to the IA component on the lateral aspect of the knee. At review, patients were thoroughly assessed with history, examination, and IKDC criteria. IKDC scores were excellent or good in 92% of patients seen while combined IKDC and thorough clinical history findings were good or excellent in 84% of patients seen. Patient satisfaction was high with 90% of patients being satisfied or very satisfied with the outcome of surgery. Activity levels were also high according to IKDC criteria. At one year postoperatively, approximately 66% of patients had returned to their preinjury level of activity. At review, almost half of all patients still maintained this level. Of those patients who did not, only 6% attributed this to knee instability. Furthermore, the vast majority of patients (92%) still had activity levels superior to that of postinjury/preoperatively. Rupture of the intra-articular component was confirmed in six cases (12%) and three of these patients continued to experience functional knee instability. These results demonstrate that synthetic ligament can provide long-term functional stability in the knee following a loss of the ACL.

Revision Anterior Cruciate Ligament Reconstruction with Doubled Semitendinosus and Gracilis Tendons and Lateral Extra-Articular Reconstruction

The outcome of revision anterior cruciate ligament reconstruction has only rarely been reported. The purpose of this study was to evaluate the results of revision anterior cruciate ligament surgery with use of an autogenous doubled semitendinosus and gracilis graft in association with an extra-articular procedure. Between 1997 and 2003, thirty patients underwent a repeat reconstruction of a previously reconstructed torn anterior cruciate ligament with use of a doubled semitendinosus and gracilis graft combined with an extra-articular reconstruction. Primary reconstruction had been done with an autogenous patellar tendon graft in twenty-six patients and with a prosthetic ligament in four patients; the average time from the primary reconstruction to the revision was five years. Functional outcomes, graft survival, and radiographic outcomes were evaluated at a mean of five years. A graft was considered to have failed when a revision was done or when the side-to-side difference on KT-1000 arthrometer testing was >5 mm and/or the pivot-shift test grade was greater than a trace. One patient underwent another revision reconstruction because of graft failure at three years postoperatively. The mean International Knee Documentation Committee (IKDC) subjective knee score for the remaining twenty-nine patients was 84 +/- 12 points, and the mean Lysholm knee score was 90 +/- 10 points. The side-to-side difference as measured with the KT-1000 arthrometer with maximum manual force was <3 mm in twenty patients (of the twenty-eight who returned for follow-up), between 3 and 5 mm in six patients, and >5 mm in two patients. The result of the pivot shift examination was normal in fifteen patients, slightly positive in eleven patients, and positive in two patients. Twenty-five percent of the patients showed no radiographic signs of degenerative joint disease. Revision anterior cruciate ligament reconstruction with use of an autogenous doubled semitendinosus and gracilis graft combined with an extra-articular procedure provided satisfactory functional outcomes, with a failure rate of 10%.

Fixation of the graft in reconstruction of the anterior cruciate ligament

Methods of reconstruction of the anterior cruciate ligament (ACL) have developed considerably over the last 15 years. Primary repair and extra-articular procedures have failed to reproduce satisfactory stability of the knee[1][1] and the use of prosthetic ligaments has been abandoned.[2][2] These

Isometry of potential suture attachment sites for the medial aspect of the tibiotarsal joint

The isometry of the bipartite medial collateral ligament of the tarsus and two methods of stabilization by prosthetic ligament were assessed by measuring the change in distance between the origin and the insertion through full range of joint motion of the ligament and prosthetic ligaments. The single suture technique was isometric when the distal site was located at the centre of the trochlea of the talus. This site can only be used when the medial malleolus, which overlies the talus, is missing or removed. Whilst some length changes occur with hock motion, the double suture technique may be advocated in instances where the medial malleolus is present.

10–16 year results of Leeds-Keio anterior cruciate ligament reconstruction

Following initial enthusiasm in the late 1980s, the use of artificial ligament substitutes for anterior cruciate ligament (ACL) reconstruction has declined. However, the disadvantages of donor site morbidity for autologous graft and concerns about cross-infection from allogenic material have resulted in a maintained interest in prosthetic ligament substitutes. This study presents the outcome of ACL substitution using the Leeds-Keio (LK) polyester ligament at a mean of 13.3 years (range 10–16 years). Outcome was assessed using the International Knee Documentation Committee score, the Lysholm knee score, Tegner activity scale and American Knee Society Score and laxity by clinical examination and the Stryker Knee Laxity Tester. Standardized radiographs were taken to assess for evidence of degenerative change. The objective scoring tests showed that all patients experienced some degree of symptoms from their knee but functional impairment varied widely. Of the group, 28% were known to have ruptured their LK ligament and 56% had increased laxity compared with their opposite knee but no correlation could be shown between rupture, increased laxity and poor function. Of particular concern, all post-operative knees had radiographic signs of degenerative change compared with a rate of 39% in the contralateral knees.

Use of the Leeds–Keio prosthetic ligament for repair of patellar tendon rupture after total knee arthroplasty

We describe a technique for repair of the patellar tendon rupture after total knee arthroplasty (TKA), using the Leeds–Keio (L-K) prosthetic ligament. Two patients were followed for a mean of 38 months. Knee extension power and improved function were obtained in both cases. Use of the L-K ligament is a treatment option for repair of patellar tendon rupture following TKA.

Computational and Experimental Study of Performance of an Artificial Ligament: DacronTM yarn

The success rate of reconstructing the Anterior Cruciate Ligament (ACL) with prosthetic ligaments is currently low both in humans and animals. The stress distribution in prosthetic ligaments that causes failure is very complex and not yet understood. Therefore, we have begun to develop a Finite Element Model of a prosthetic ACL. Here we describe the normal and contact stresses in DacronTM yarn (a multi-fibrillar structure) using input data based on experimental measurements of the load and strain of six designed yarns. The results show that the normal and contact stresses in the fibres of the ACL yarn are directly proportional to the yam strains. Increasing the twisting length (transverse deformation) of the yarn increases the normal stress in the fibres and the yarn modulus, but decreases the contact stresses between the fibres. The structural properties of a yarn are dependent on the specific arrangement of various filament types. Increasing the distance between the longitudinal (symmetry) axes of the filaments and the axis of symmetry of the yarn decreases the stresses.

The Ligament Augmentation Device: An Historical Perspective

Summary: Anterior cruciate ligament (ACL) injury is the most common ligament injury in the knee, and a significant number of patients may develop progressive instability and disability despite aggressive rehabilitation. Various materials have been used for its reconstruction. These include autografts, allografts, prosthetic ligaments, and synthetic augmentation of the biological tissue. The concept of ligament augmentation device (LAD) arose from the observation that biological grafts undergo a phase of degeneration and loss of strength before being incorporated. The LAD is meant to protect the biological graft during this vulnerable phase. However, it provokes an inflammatory reaction in the knee, and has been found to delay maturation of autogenous graft in humans. In experimental situations, the LAD has been found to share loads in a composite graft. It has also been found to be substantially stronger than the biological graft. However, in clinical situations no significant advantages have been observed with the use of LAD to augment patellar tendon or hamstring reconstruction of the chronic ACL-deficient knee or in the acute setting to augment repair of the torn ACL. There are very few reports of the use of LAD in reconstruction of the posterior cruciate ligament, and again these do not suggest any advantage in its use. Insertion of the LAD implies the introduction of a foreign material into the knee, has been associated with complications such as reactive synovitis and effusions, and may also be associated with an increased risk of infection. At present, there is no evidence that its routine use should be advocated in uncomplicated reconstructions of the ACL using biological grafts. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 15, No 4 (May-June), 1999: pp 422–432

Evaluation of joint stabilization for treatment of shearing injuries of the tarsus in 20 dogs.

Medical records of 20 dogs with 23 shearing injuries of the tarsus leading to joint instability were reviewed. A transarticular external skeletal fixation device or prosthetic ligament was used to stabilize the joints. The most common complications were fixator failure and implant infection. The median times for wound healing and maximal joint function were 10 and 12 weeks, respectively. Clinical outcome was excellent in 22%, good in 56%, and poor in 22%. Comparison of the two stabilization methods showed no statistically significant differences in healing time, time to regain function, or clinical outcome.

Closed Toggle Pinning for Canine Traumatic Coxofemoral Luxation

SummaryA method of closed implantation of a toggle pin bone anchor and prosthetic ligament was developed for the treatment of traumatic canine coxofemoral luxation. Radiographic and anatomical evaluation of the canine femur and acetabulum were performed in order to develop an imaging and instrumentation technique that would allow closed placement of a toggle pin bone anchor under fluoroscopic guidance, while at the same time minimizing, or eliminating, damage to the articular cartilage. The surgical technique was then performed in 14 canine cadaver coxofemoral joints, followed by gross evaluation of implant placement, and potential cartilage or soft tissue damage. The cervical canal radiographic view of the proximal femur allowed placement of the drill hole through the fovea capitis of the femoral head without damaging the articular cartilage. The acetabular fossa was readily distinguishable from the acetabular articular cartilage on both of the lateral and ventrodorsal radiographic views of the pelvis. The toggle pin apparatus was inserted without damage to the articular cartilage in nine out of the fourteen hips and the bone tunnels were situated within the cancellous bone of the femoral neck in each of the nine specimens evaluated. Complications encountered during the procedure included bending and/or breakage of the guide wire in three hips and damage to the articular cartilage in two hips. The success of technique modifications designed to diminish the incidence of these complications awaits investigation in a clinical trial. Closed toggle pinning for canine traumatic coxofemoral luxation has the potential advantage of achieving rapid stabilization of the coxofemoral joint without damage to the articular cartilage and the need for an open approach to the joint. The clinical application of the technique is reported in one patient.The equipment and methodology for closed implantation of a toggle pin bone anchor and prosthetic ligament was developed for the treatment of traumatic coxofemoral luxation. A cadaver study was performed to assess the viability of the technique. Clinical application in one case is described.

A comparison of the effectiveness of currently available instrumentation for radiusing bony tunnel exits in cruciate ligament reconstruction

Mode of failure analyses of explanted prosthetic ligaments and clinical MRI studies of autologous reconstructions have identified that the position of the exit of the tibial tunnel is critical for the survival of an intra-articular reconstruction of the anterior cruciate ligament. When drilling the tibial tunnel, the position of the exit must be positioned behind the roof and apex of the intercondylar notch in the extended knee if implant impingement is to be avoided. Inadequate radiusing of the exits of tibial and femoral tunnels is also likely to be another factor leading to localised rupture, or graft complications in this type of surgery. A prospective comparative study was performed to determine the effectiveness of existing instruments available for radiusing the drill hole exit. This has resulted in the development of a modified back radius cutter, which provides effective and consistent removal of sharp edges at the margins of bony tunnels.

Rehabilitation following patellar tendon or ABC prosthetic ligament reconstruction for chronic anterior cruciate ligament deficient knees

In a prospective comparative study, 39 patients underwent ACL reconstruction under arthroscopic control. Twenty patients had reconstruction with a prosthetic ligament, ABC (Surgicraft, Redditch, UK) 19 patients had reconstruction with a free, autogenous, middle one third Patellar tendon. The purpose of this study was to assess any early advantage in using the ABC prosthetic ligament to achieve better function at the end of 6 months of rehabilitation. It is also intended to follow-up these patients in the long term. At the end of rehabilitation there was no statistically significant functional difference between the two groups and any differences in scores was attributed to the higher incidence of extensor lag and pain in the patellar tendon group. We concluded from this initial study that any accelerated rehabilitation, which may follow reconstruction with the ABC prosthetic ligament, is not significant at the end of a 6-month rehabilitation phase when compared to autologous Patellar tendon replacement, and we cannot therefore justify use of prosthetic ligaments on the grounds of rapid rehabitation.

Computer Assisted Knee Surgery: Diagnostics and Planning of Knee Surgery

Cruciate ligament rupture, a common injury among young active adults, disrupts the knee's complex movement and often leads to premature degenerative arthritis of the joint. Prosthetic cruciate ligaments can be used for replacement but often fail owing to incorrect surgical placement. To aid in die planning of cruciate prosthetic substitution, a computerized system has been developed to provide the surgeon with a virtual interface allowing accurate visualization of three-dimensional (3D) bone structure and movement normally hidden beneath layers of soft tissue.Preoperatively, precise in vivo kinematics are quantified with the help of 3D medical images. Three-dimensional imagery techniques based on computed tomography (CT) have been developed to obtain accurate 3D reconstruction of knee geometry preoperatively. The system allows the surgeon to know the real-time spatial position of the patient via magnetic position and orientation sensors attached noninvasively onto the femur and tibia via a new attachment system. An interactive computer program has been developed to allow the user to simulate different prosthetic ligament insertions and compute elongation, bending, and torsion values that will be imposed on the prosthesis. Through comparison with cadaver studies and a perturbation analysis, the system is shown to be sufficiently accurate to predict certain in vivo ligament bending and torsion deformations.

Improving in vivo knee kinematic measurements: application to prosthetic ligament analysis

The accuracy of three-dimensional (3D) in vivo knee measurement is presently limited by artifacts from movement of soft tissue surrounding the underlying bone. To improve 3D measurement, a mechanical fixation system is proposed which attaches sensors onto the underlying bone non-invasively. A 3D X-ray technique is used to show that the system can measure knee kinematics over 65° flexion with an average accuracy of −0.4° ab-adduction rotation, −2.3° for axial rotation, 2.4 mm for antero-posterior translation and 1.1 mm for axial translation. To demonstrate a clinical application of the system, its use to predict prosthetic ligament bending and torsion deformations in vivo is reported.

Revision of failed prosthetic anterior cruciate ligament reconstruction.

Revision of failed prosthetic anterior cruciate ligament reconstructions will continue to be necessary as previously placed prosthetic devices fail with time. These patients often present with recurrent instability, pain, swelling, or effusions. Graft rupture and the generation of particulate debris are common causes of these symptoms. To effectively treat these patients requires careful preoperative evaluation and planning. Operative treatment includes removing the prosthesis and metal fixation devices, evaluating femoral and tibial bone stock, and determining adequacy of previous tunnel position. Staging of the operation may be a necessity if significant bone loss or poor tunnel position on either the femoral or tibial side requires bone grafting. The use of an autogenous bone-patellar tendon-bone graft is suggested and has proven to be effective in restoring knee stability in these revision cases. The ultimate outcome following revision of failed prosthetic ligaments may be limited by associated intraarticular pathology often seen in this patient population.

Long-term results of the Leeds-Keio anterior cruciate ligament reconstruction.

This paper discusses the long-term results of the anterior cruciate ligament (ACL) reconstruction with the Leeds-Keio (LK) prosthetic ligament. For this type of reconstruction we used arthrotomy and an arthroscopy-assisted technique. The fixation was obtained with two bone plugs, and the distal portion was also attached with a staple. A postoperative protocol was used with a progressive range of motion and weight bearing after 50 days. We performed 50 LK operations in professional and amateur athletes aged 17-39 years with an isolated anterior instability. We reviewed at follow-up (5-7 years) 37 patients; 8 were lost, and 5 had a subsequent failure. At the Lysholm score the patients were classified: 19 excellent, 13 good, 3 fair, and 2 poor. At the IKDC grading the patients were classified as follows: 2 class A, 22 B, 8 C, and 5 D. The Lachmann test was 1+ in 15 patients, 2+ in 7, 3+ in 2, and negative in 13; pivot shift was 1+ in 9, 2+ in 7, 3+ in 2, and negative in 25. Results of the KT 1000 test at 30 lb side to side was < 3 mm in 23 patients, 3-5 mm in 6, 6-10 mm in 6, and > 10 mm in 2. In view of the results observed and the progressive deterioration over the years, this procedure should no longer be performed as an ACL substitute.

Histological changes associated with an artificial anterior cruciate ligament.

To investigate the histopathological features of the synovial lining of the knee following implantation of an artificial cruciate ligament. Eighty two patients underwent anterior cruciate ligament reconstruction for chronic, symptomatic instability of the knee. The cruciate ligament was reconstructed with a scaffold type prosthetic ligament. All patients underwent arthroscopy at the time of cruciate reconstruction and also as a "second look" procedure at a mean 26.5 months later, at which time synovial biopsy specimens were obtained in all cases. The most frequent histological finding was granulomatous synovitis in 48% (39/82) of patients. Particulate polyester debris produced a greater response than carbon fibres. In 24% (20/82), nonspecific inflammation was present and in 28% (23/82) the synovium was considered normal. When the prosthetic ligament was fully covered by soft tissue in-growth, a granulomatous reaction was present in 42% (24/57), irrespective of whether the ligament was partially or totally uncovered. Stabilisation of the joint did not prevent subsequent deterioration in the articular cartilage; other factors such as increasing patient age, interval between injury and reconstruction and altered knee kinematics after reconstruction are probably important. Granulomatous synovitis was not associated with progressive chondral changes. Although present in 48% of cases, granulomatous synovitis was not shown to have adverse effects on either chondral surface or the prosthetic material of the ligament. Rupture of the implant is caused by mechanical factors and granulomatous synovitis is not responsible for implant failure.

The effect of patient age on failure rates of a prosthetic anterior cruciate ligament

osteochondral cylinders were on the superolateral and anterolateral aspects of the lateral femoral condyle. Initially, autografts were harvested with modified standard 5 and 10 mm bone trephines, but from 1994 thin-walled tubular instruments with fine serrated cuttine edges orieinallv designed for ACL reconstruction were spiciall; adaptzd and were used routinely. The recipient site was prepared in a similar manner and the osteochondral cylinder press-fitted. The bone cylinder removed from the recipient area was routinely inserted in the donor area. Lysholm scores after surgery. Implantation of a prosthetic ACL should perhaps be limited to patients over the age of 30 years.