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

Time-series biological responses toward decellularized bovine tendon graft and autograft for 52 consecutive weeks after rat anterior cruciate ligament reconstruction

There is an essential demand for developing biocompatible grafts for knee anterior cruciate ligament reconstruction (ACLR). This study investigated cell infiltration into decellularized bovine tendon xenografts using a rat knee ACLR model. Twelve-week-old Sprague–Dawley rats were used. At weeks 1, 2, 4, 8, 16, 26, and 52 (each period, n = 6) after ACLR, rats receiving decellularized bovine tendon (group D, n = 42) or autologous tendon (group A, n = 42) as grafts underwent peritibial bone tunnel bone mineral density (BMD), histological, and immunohistological assessments. BMD increased over time in both the groups until week 16 and then remained unchanged without exhibiting significant differences between the groups. Initially, cellularity in group D was lower than that in group A; however, by weeks 4–8, both the groups were comparable to the native anterior cruciate ligament group and cellularity remained unchanged until week 52. Initially, group A had more M1 macrophages, indicating inflammation, whereas group D had more M2 macrophages, indicating tissue regeneration. Nonetheless, the M1 and M2 macrophage counts of both the groups were comparable at most times. This study revealed the excellent recellularization and tendon–bone integration abilities of decellularized tendons using a cross-species model.

Adolescent Quadriceps Tendon Rupture, an Early Complication After ACL Reconstruction: A Case Report

CASE

A healthy adolescent male patient initially presented with complete rupture of the anterior cruciate ligament (ACL) after a plant-twist injury during a high school football game. Four weeks after ACL reconstruction with autograft bone-patella tendon-bone, the patient slipped and fell, sustaining hyperflexion of the knee, resulting in rupture of the ipsilateral quadriceps tendon.

CONCLUSION

Although this rare complication has previously been reported in the adult population, to the best of our knowledge, this is the first known report of an adolescent patient sustaining a quadriceps tendon rupture after ACL reconstruction.

Comparison of knee extensor strength after anterior cruciate ligament reconstruction using either quadriceps tendon or hamstring tendon autografts

PURPOSE

The aim was to assess the consequences of quadriceps tendon (QT) harvest on knee extensor strength after anterior cruciate ligament reconstruction (ACL-R) compared to hamstring tendon (HT) autograft. Secondary objectives were to evaluate flexor strength recovery and search for correlation between strength status and functional outcome.

METHODS

This a retrospective cohort of 44 patients who underwent ACL-R using either QT (25) or HT (19). Median age was 31.1 years. We assessed thigh muscle strength thanks to concentric iso kinetic evaluation (peak torque) at 60°.s^-1, 180°.s^-1, 240°.s^-1 and eccentric at 30°.s^-1, 7 months on average after surgery. Muscle strength values were compared to the uninjured leg in order to calculate a percentage of deficit as well as unilateral hamstring/quadriceps (H/Q) ratios. KOOS score was obtained at a mean follow-up of 18 months.

RESULTS

Extensor strength deficit (concentric 60°.s^-1) was one average 33.1% in the QT group and 28.2% in the HT group (p = 0.42). Difference of flexor strength deficit (concentric 60°.s^-1) was close to be significant with 5% and 12% of deficit in the QT and HT group, respectively (p = 0.1), and statistically significant for high angular velocity (14% versus 3% at 240°.s^-1, p = 0.04). H/Q ratios were comparable in both groups ranging from 0.62 to 0.78. Quadriceps muscle strength deficit was negatively correlated with the KOOS score (Pearson coefficient = -0.4; p = 0.005).

CONCLUSION

QT autograft harvest does not yield significant quadriceps muscle weakness after ACL-R, which appear to be a pejorative factor for functional outcome.

LEVEL OF EVIDENCE

IV, Retrospective study.

Prevalence of patellofemoral joint osteoarthritis after anterior cruciate ligament injury and associated risk factors: A systematic review

Background

The prevalence of patellofemoral joint (PFJ) osteoarthritis (OA) after anterior cruciate ligament (ACL) injury was inconsistently reported in the literature. This review summarises the reported prevalence of PFJ OA and risk factors of PFJ OA after ACL injury.

Methods

PubMed, Embase, WoS, and MEDLINE (OVID) were searched up to 1 March 2019. A modified version of the Coleman methodology score was used to assess the methodological quality of the included studies. Prevalence of PFJ OA was pooled depended on different interventions in ACL injured populations.

Results

Thirty-eight studies were included. Five different radiographic classification methods were used: the Kellgren and Lawrence Grade 2, IKDC Grade B, Fairbank Grade 1, joint space narrowing of Grade 2 based on OARSI, and Ahlbäck Grade 1. One included study used MRI Osteoarthritis Knee Score to evaluate PFJ degenerative changes. The overall prevalence of PFJ OA after ACL injury in included studies varied between 4.5% and 80%. The large variation of PFJ OA prevalence is mainly because of different follow-up period and surgical techniques. The pooled data showed that bone-patellar tendon-bone graft, single-bundle ACL reconstruction (ACLR), and delayed ACLR are likely associated with PFJ degenerative changes after ACL injury. ACLR, delayed ACLR, body mass index (BMI), meniscectomy, patellofemoral chondral lesions, age at surgery, and TFJ OA were identified in the literature inducing PFJ OA after ACL injury.

Conclusions

Large variations of PFJ OA after ACL injury are associated with different follow-up period and surgical techniques. ACL reconstructed population with bone-patellar tendon-bone graft, single-bundle reconstruction, and delayed operation time has a high prevalence of PFJ OA.

The translational potential of this article

This review focuses more on the effect of surgical technique factors on the degenerative changes on PFJ. The results reveal that BPTB, single-bundle reconstruction, and delayed ACLR are more likely associated with PFJ degenerative changes after ACL injury. These findings imply that awareness of PFJ problems after surgical intervention will remind of surgeons taking PFJ into consideration in operations, which is likely to reduce the incidences of anterior knee pain, patellar maltracking, and over-constrained patella in the early stage after surgery.

Shear wave elastography of the healing human patellar tendon following ACL reconstruction

PURPOSE

Anterior cruciate ligament (ACL) ruptures are common and are frequently reconstructed using a patellar tendon (PT) autograft. Unfortunately, the time course of PT healing after ACL reconstruction is not particularly well understood. Thus, the primary objective of this study was to use shear wave elastography (SWE) to evaluate the extent to which shear wave speed (SWS) is associated with time after ACL reconstruction.

METHODS

Longitudinal SWE images were acquired from lateral, central, and medial regions of the PT from two groups: 30 patients who had undergone ACL reconstruction with a PT autograft within the preceding 40 months, and 30 age-matched asymptomatic control subjects. SWE images were acquired at 20° and 90° of passive flexion from both knees. In each subject group, statistical analyses assessed changes in mean SWS with time post-surgery, as well as differences in mean SWS between PT regions and limbs.

RESULTS

In the ACL reconstruction patients, mean SWS increased with time post-surgery in the lateral region of the involved knee (p = 0.025) and decreased with time post-surgery in the central region of the contralateral knee (p = 0.022).

CONCLUSION

The findings suggest that there is an association between the mechanical properties of the PT and time post-surgery in both the involved and contralateral limbs after ACL reconstruction. These changes are likely due to maturation of the donor site tissue and changes in gait/loading patterns following ACL rupture and reconstruction.

LEVEL OF EVIDENCE

Level II - Prospective Cohort.

Ceramic Bone Graft Substitutes do not reduce donor-site morbidity in ACL reconstruction surgeries: a pilot study

INTRODUCTION

Anterior knee pain is a major problem following Bone-patellar-tendon-bone graft (BPTB) use in anterior cruciate ligament (ACL) reconstruction. We hypothesized that filling the donor defect sites with bone-graft substitute would reduce the anterior knee symptoms in ACL reconstruction surgeries.

MATERIAL AND METHODS

Patients operated for ACL-deficient knee between March 2012 and August 2013 using BPTB graft were divided into two treatment groups. The patellar and tibial donor-site bony defects were filled-up with Hydroxyapatite-Bioglass (HAP:BG) blocks in the study group (n = 15) and no filler was used in the control group (n = 16). At 2 years, the clinical improvement was assessed using International Knee Documentation Committee (IKDC) score and donor-site morbidity was assessed by questionnaires and specific tests related to anterior knee pain symptoms.

RESULTS

Donor-site tenderness was present in 40% patients in the study group and 37.5% patients in the control group (p = 0.59). Pain upon kneeling was present in 33.3% patients in the study group and 37.5% patients in the control group (p = 0.55). Walking in kneeling position elicited pain in 40% patients in the study group and 43.8% in the control group (p = 0.56). The mean visual analogue score for knee pain was 3.0 in the study group and 3.13 in the control group, with no statistically significant difference (p = 0.68). Unlike control group, where a persistent bony depression defect was observed at donor sites, no such defects were observed in the study group.

CONCLUSION

Filling the defects of donor sites with HAP:BG blocks do not reduce the anterior knee symptoms in patients with ACL reconstruction using autogenous BPTB graft.

Anterior knee pain following BPTB graft harvest. Reality or overhyped

INTRODUCTION

The patellar tendon graft has long been the gold standard for ACL reconstruction. Recently semitendinosus and gracilis tendons graft have been used increasingly. We hypothetise that the Bone-Patella Tendon-Bone graft is a good and economical graft for the Indian population with no adverse effects of anterior knee pain or patellar tendon shortening. We believe that the early squatting and cross-legged sitting causes early and constant stretching of the tendon in our patients. This is responsible for the lesser incidences of adverse effects in the Indian population.

MATERIAL AND METHOD

In a retrospective study, the hospital database was scrutinized to shortlist patients who had undergone a bone-patella tendon-bone harvest for ACL or PCL reconstruction before 2013. Each patient was evaluated using the Lysholm score and the KOOS Score. VAS was also used, to evaluate for the amount of pain experienced by patients. The analysis of the quadriceps power along with the presence or absence of any extensor lag was made too. The modified Insall Salvati index was also calculated.

RESULTS

Forty-seven patients were shortlisted of which 25 patients were followed up with an average follow up of 94.5 months. Although some patients did complain of occasional pain with the average VAS score of 1.45; on analyzing the data it was evident that all our patients had excellent quadriceps power (5/5) with no extensor lag. The mean Lysholm score was 95.55, while the mean KOOS score was 94.17. The mean Insall index of 1.05 showed no significant patella baja in any of our patients.

CONCLUSION

It is ascertained that no significant retro-patellar pain or shortening of the patellar tendon occurs following a bone patella tendon bone harvest. The bone patella bone tendon graft is a suitable graft for ligament reconstruction with good functional outcome, and no significant adverse effect of patella baja or anterior knee pain in the Indian patients.

LEVEL OF EVIDENCE

Level IV.

Intraoperative patellar kinematics following resection of the central one-third of the patellar tendon in the ovine stifle joint

Objectives: The bone-patellar tendon-bone complex is routinely harvested for anterior cruciate ligament reconstruction in humans. Patella infera may ensue. However, the contribution from resection of the central one-third of the patellar tendon (PT) to potentially altered patellofemoral kinematics, in addition to those induced by a positional shift of the patella, are yet to be distinguished. Objectives of this study were to characterize changes in intraoperative patellar kinematics and PT length in nine sheep immediately following unilateral resection of the central one-third PT, and again at six, 12 and 24 weeks postoperatively.

Methods: Following implantation of bone-screws into the patella and tibia, electromagnetic receivers were anchored to these, and then passively-induced, unloaded patellar kinematics were captured. Patellar kinematics were referenced to the tibial coordinate frame and analysed using non-parametric tests (Wilcoxon Signed Rank Test).

Results: Resection alone did cause significant alteration in kinematics at the time of surgery (p <0.05). Postoperatively, a mean increase in PT length of 2.6 mm was detected in the operated stifles, reflected partly as a net 2.8 mm proximal patellar shift (p <0.001). This was accompanied by a mean net six degree medial shift in the patellar tilt pattern (p <0.001). Significant changes to patellar spin in the latter parts of flexion were also observed (p <0.005). Kinematic and length changes did not recover up to 24 weeks postoperatively.

Clinical significance: The data obtained in this study suggests that both the patellar height and integrity of the PT are important determinants of patellar kinematics in the ovine stifle joint.

Complications following harvesting of patellar tendon or hamstring tendon grafts for anterior cruciate ligament reconstruction: Systematic review of literature

Anterior cruciate ligament (ACL) reconstruction can be performed with an autograft, which is most often harvested from the patient's hamstring tendon (HT) or patellar tendon (PT). However, autograft harvesting leads to morbidity that is by no means insignificant. A systematic review of literature was performed to define the incidence of complications related to graft harvesting and the methods to prevent these complications. In March 2017, a systemic review of literature was performed using the keywords"harvesting", "harvest", "morbidity", "complication", "cruciate ligament". No time limit was applied. The studies had to be written in French or English with their abstract available online. This initial search based on the title and abstract identified 133 articles. Two independent observers analyzed each article entirely, including the references. In all, 36 articles were retained. The main complication of HT harvesting was sensory deficit because of damage to the infrapatellar branches of the saphenous nerve. This complication occurred in 39.7% to 88% of patients. This risk can be reduced by using a horizontal or oblique incision. The main complication following PT harvesting is anterior knee pain, reported in up to 46% of patients. There are substantial numbers of short-, medium- and long-term complications related to the harvesting of the two main ACL autografts. Effective means of prevention exist to reduce the risk of these complications.

LEVEL OF EVIDENCE

II Systematic review of literature.

Association of fibrosis in the infrapatellar fat pad and degenerative cartilage change of patellofemoral joint after anterior cruciate ligament reconstruction

BACKGROUND

The purpose of this study was to evaluate the prevalence and risk factor of cartilage degeneration of the patellofemoral joint (PFJ) that was diagnosed by second-look arthroscopy.

METHODS

One-hundred and seven patients who underwent ACL reconstruction were evaluated by preoperative MRI, postoperative MRI and second-look arthroscopy. Severity of infrapatellar fat pad (IPFP) fibrosis was evaluated by MRI at an average of 26months after ACL reconstruction. Cartilage degeneration was assessed by second-look arthroscopy at 29months.

RESULTS

Twenty-five patients (24.0%) showed cartilage degeneration of the PFJ in second-look arthroscopy. Patients were divided into three groups according to severity of IPFP fibrosis of postoperative MRI (i.e. Group A, focal and incomplete band fibrosis, n=69; Group B, complete band fibrosis, n=31; and Group C, diffuse and infiltrated fibrosis, n=7). Cartilage degeneration of the PFJ was significantly worsened with more fibrosis formation of the IPFP (P<0.001). Other factors for instabilities (BMI, age, concomitant meniscal procedure, time from injury to reconstruction, severity of IPFP fibrosis at preoperative MRI and clinical scores) were not correlated with cartilage degeneration of the PFJ. The multivariate logistic regression analysis of degeneration of the PFJ after ACL reconstruction identified more severe fibrosis tissue formation of the IPFP and initial cartilage defect as significant predictors.

CONCLUSIONS

More extensive fibrosis of the IPFP and initial cartilage defect may be related to further degenerative changes of the PFJ. Other factors did not affect cartilage degeneration of the PFJ, although the muscle strength, the individual activity level or the rehabilitation protocol was not evaluated in the short-term follow-up period.

Anterior cruciate ligament reconstruction with bone-patellar tendon-bone autograft versus allograft in skeletally mature patients aged 25 years or younger

PURPOSE

The purpose of this study is to evaluate the clinical outcomes and revision rates of skeletally mature patients aged 25 years or younger who have undergone either BPTB autograft or deep-frozen, non-irradiated BPTB allograft ACL reconstruction by a single surgeon.

METHODS

Two hundred and twenty-four patients aged 25 or younger at the time of surgery were identified as having a transtibial ACL reconstruction with either a BPTB autograft or deep-frozen, non-irradiated BPTB allograft by one senior surgeon (101 autografts vs. 123 allografts) over the study time period. Primary outcome measure included the need for ACL revision. One hundred and nineteen patients with at least 2-year clinical follow-up agreed to participate in secondary outcome measurement arm of the study and were administered the Lysholm Knee Scoring Scale and IKDC Subjective Knee Evaluation Form.

RESULTS

The median Lysholm scores were 95 (40-100) and 95 (68-100) and the median IKDC scores were 95.4 (54.0-100) and 95.4 (72.4-100) in the allograft and autograft groups, respectively. The differences in the Lysholm scores and the IKDC scores were not statistically significant (P = n.s.). There were 13 patients requiring ACL revision, 12 allograft versus one autograft (P = 0.005).

CONCLUSION

Although there is no significant difference in patient-rated outcome between ACL reconstructions using BPTB autografts versus BPTB allografts, a significantly higher rate of ACL revision was found in allograft patients. The results of our study support a growing body of literature that BPTB autograft reconstruction leads to lower retear rates in younger individuals, an important factor in the graft selection process for these patients.

LEVEL OF EVIDENCE

III.

A meta-analysis of anterior cruciate ligament reconstruction with autograft compared with nonirradiated allograft

BACKGROUND

To compare autograft with non-irradiated allograft for reconstruction of anterior cruciate ligament.

METHODS

MEDLINE, EMBASE, and Cochrane Library databases, as well as unpublished and ongoing studies were searched through up to 20 July 2013 to identify studies meeting the pre-stated inclusion criteria.

RESULTS

A total of 12 studies (n=1167, including 597 patients in the autograft group and 570 patients in the allograft group) were included. The methodological scores for randomized controlled trials ranged from two to four (total score: seven), and for non-randomized prospective studies and cohort studies ranged from four to seven (total score: 12). Except for the Lysholm score (WMD, -1.46; P<0.05) showing a statistically significant difference but a small and clinically irrelevant difference, there was no significant difference between autograft and non-irradiated allograft with respect to the overall IKDC (International Knee Documentation Committee) level, subjective IKDC score, Tegner score, complication, ROM (range of motion), Pivot-shift test, Anterior drawer test, Lachman test, Daniel's one-leg hop test, Harner's vertical jump test, and Instrumented knee laxity test. The results were consistent across a series of sensitivity analyses and subgroup analyses.

CONCLUSIONS

Patients with autograft exhibited little clinical advantage over non-irradiated allograft with respect to knee stability, function and side effects. The robustness of the findings might need to be further validated due to the relatively small number of randomized controlled trials.

LEVEL OF EVIDENCE

Level II, meta-analysis of prospective studies.

Anterior cruciate ligament reconstruction using achilles tendon allograft: an assessment of outcome for patients age 30 years and older

Achilles allografts have become popular for anterior cruciate ligament (ACL) reconstructions in older patients. Primary ACL reconstructions using Achilles tendon allografts in patients age 30 years and older are successful in restoring the knee to "normal" or "near normal." During a three-year period, the two senior authors performed 65 primary ACL reconstructions using Achilles tendon allografts in patients aged 30 years and older. Our exclusion criteria were periarticular fracture, ipsilateral/contralateral knee ligament injury, and previous or concomitant osteotomy or cartilage restoration procedure. Each patient was evaluated via physical examination, functional and arthrometric testing, and radiographic and subjective outcome. Knees were considered normal, near normal, or abnormal based on the International Knee Documentation Committee (IKDC) system. Forty-three patients were examined at an average of 33 months (minimum, 24 months) postoperatively. At the time of ACL reconstruction, 35% had normal articular cartilage in all three compartments and 70% had meniscal tears. No re-ruptures occurred. While 24% had mean maximal translation differences less than or equal to 3 mm, none had side-to-side differences greater than 5 mm. Postoperative IKDC, Activities of Daily Living, and Activity Rating Scale scores averaged 88, 94, and 7.7, respectively. Despite the overall favorable outcomes, 29% had worsened radiographic grades at follow-up. Using an Achilles allograft for ACL reconstruction in patients older than 30 years, we restored over 90% of knees to normal or near normal while limiting postoperative complications. Poor subjective results may be related less to instability and more to pain, which may result from progressive arthritis.

Effect of electron beam irradiation on biomechanical properties of patellar tendon allografts in anterior cruciate ligament reconstruction

BACKGROUND

Sterilization of anterior cruciate ligament (ACL) allografts is an important prerequisite to prevent disease transmission. However, mechanical tissue properties are compromised by most current sterilization procedures, so that uncompromised sterilization of allografts is difficult to achieve. Hypothesis/

PURPOSE

The aim of this study was to evaluate the effect of the novel electron beam sterilization procedure on the biomechanical properties of human patellar tendon allografts at various irradiation dosages. Electron beam sterilization may be an appropriate alternative to gamma sterilization.

STUDY DESIGN

Controlled laboratory study.

METHODS

Thirty-two human 10-mm wide bone-patellar tendon-bone grafts were randomized into 4 groups of sterilization with 15, 25, or 34 kGy of electron beam irradiation, respectively. The grafts' biomechanical properties were evaluated at time zero. Unsterilized grafts functioned as controls. Biomechanical properties were analyzed during cyclic and load-to-failure testing.

RESULTS

Strain and cyclic elongation response showed no significant differences between the groups. Electron beam irradiation had no significant effect on stiffness and failure load with the exception of 34 kGy, which resulted in a significant decrease in failure load (1300.6 +/- 229.2 N) compared with unsterilized grafts (1630.5 +/- 331.1 N).

CONCLUSION

This study showed that electron beam might be an appropriate alternative in sterilization of patellar tendon allografts with minimal effect on mechanical properties of tendon grafts in vitro. Future studies will have to evaluate the effect of the process on the biological properties of allografts in vitro and in vivo.

CLINICAL RELEVANCE

Terminal sterilization of patellar tendon allografts with electron beam irradiation can ensure higher safety of transplanted grafts and hence improve patient safety and acceptance.

Functional tissue engineering of ligament healing

Ligaments and tendons are dense connective tissues that are important in transmitting forces and facilitate joint articulation in the musculoskeletal system. Their injury frequency is high especially for those that are functional important, like the anterior cruciate ligament (ACL) and medial collateral ligament (MCL) of the knee as well as the glenohumeral ligaments and the rotator cuff tendons of the shoulder. Because the healing responses are different in these ligaments and tendons after injury, the consequences and treatments are tissue- and site-specific. In this review, we will elaborate on the injuries of the knee ligaments as well as using functional tissue engineering (FTE) approaches to improve their healing. Specifically, the ACL of knee has limited capability to heal, and results of non-surgical management of its midsubstance rupture have been poor. Consequently, surgical reconstruction of the ACL is regularly performed to gain knee stability. However, the long-term results are not satisfactory besides the numerous complications accompanied with the surgeries. With the rapid development of FTE, there is a renewed interest in revisiting ACL healing. Approaches such as using growth factors, stem cells and scaffolds have been widely investigated. In this article, the biology of normal and healing ligaments is first reviewed, followed by a discussion on the issues related to the treatment of ACL injuries. Afterwards, current promising FTE methods are presented for the treatment of ligament injuries, including the use of growth factors, gene delivery, and cell therapy with a particular emphasis on the use of ECM bioscaffolds. The challenging areas are listed in the future direction that suggests where collection of energy could be placed in order to restore the injured ligaments and tendons structurally and functionally.

Factors affecting patients' graft choice in anterior cruciate ligament reconstruction

Background

Multiple studies have reported that allografts are acceptable alternatives to autografts for anterior cruciate ligament (ACL) reconstructions. Our clinical practice allows patient involvement in graft decision-making. This study examined the patients' preference for graft selection and the factors affecting their decision.

Methods

Patients scheduled to undergo an ACL reconstruction surgery (n = 129) at a university medical center in Korea were enrolled in this study. Information leaflets with graft descriptions were provided prior to hospital admission, and the patients were allowed to choose one of two surgical graft types. The patients were asked to complete a questionnaire that reflected their decision-making processes, and the patients' trends and factors affecting their choice of graft were analyzed based on their responses.

Results

Most patients (54.3%) selected autografts for the ACL reconstruction. The surgeon's explanation was the most important factor affecting the final patient decision followed by the information derived from Internet searches. Patients who derived the majority of their understanding of the graft types from the Internet chose allografts at significantly higher rates.

Conclusions

Patient graft selection is a reasonable way of designating the type of surgical procedure. Most patients selected autografts for their ACL reconstruction. However, patients who performed significant Internet-based research tended to prefer allografts.

[Late patellar tendon rupture 10 years after anterior cruciate ligament reconstruction using a bone-patellar tendon-bone graft]

Autologous transplantation of the central third of the patella tendon with a bone-patellar tendon-bone (BTB) graft is one of the most commonly used techniques for anterior cruciate ligament (ACL) reconstruction. Frequently chosen alternative sources include semitendinosus and gracilis tendon autografts. The differences of opinion regarding graft sources mainly result from comparison of outcome and complications. Although higher donor site morbidity and postoperative extensor mechanism complications are postulated for bone-patellar tendon-bone grafts, patellar tendon ruptures following anterior cruciate ligament reconstruction are rarely reported in the literature. These predominantly occur during the early postoperative period. We present the case of a patellar tendon rupture in a healthy 36-year-old man, who suffered a skiing accident 10 years after uneventful ACL reconstruction with a BTB graft.

Anatomic ACL reconstruction: does the platelet-rich plasma accelerate tendon healing?

Recently, the use of hamstring tendons in anterior cruciate ligament repair has been increasing. However, tendon-to-bone healing occurs slowly, which can be a problem to an early return to sport activities. The use of growth factors from platelets seems to improve tissue healing. We enrolled 40 patients in a prospective study that were submitted to an anatomic reconstruction of the anterior cruciate ligament. Patients were sequentially enrolled into four groups: group A without platelet-rich plasma (PRP); group B with PRP in femoral tunnels at the end of surgery; group C with PRP in femoral tunnels at the end of surgery and intra-articular at 2- and 4 weeks after surgery; group D with PRP activated with thrombin in the femoral tunnels. All patients underwent magnetic resonance imaging of the knee 3 months after surgery to evaluate the signal intensity of the fibrous interzone (FIZ) in the femoral tunnels. We did not find any difference among the groups when comparing the signal intensity of the FIZ on magnetic resonance imaging.

Ankle morbidity after autogenous Achilles tendon harvesting for anterior cruciate ligament reconstruction

Although several alternative autografts with reduced morbidity of harvest site have been introduced, no donor site is free of morbidity concerns. The authors report on ankle status after autogenous Achilles tendon harvesting with a minimum 10-year follow-up. From October 1994 to October 1996, a consecutive series of 47 ankles underwent harvesting of the medial third or half of the ipsilateral autogenous Achilles tendon for primary anterior cruciate ligament reconstruction. Donor site statuses were evaluated using a modified Thermann's scale. Postoperative isokinetic muscle strength testing was performed, and magnetic resonance images of donor sites were available for selected patients. Thirty-three ankles in the 32 patients were followed for more than 10 years. There were 27 men (84%) and 5 women (16%) with a mean age of 31 years (range 16-52 years) at the time of surgery. The mean duration of follow-up was 12 years and 1 month (range 10 years and 5 months to 13 years and 4 months). Mean postoperative modified Thermann's scale score was 87 (range 45-95; SD 14.3). Twenty-five (76%) ankles achieved very good or good results. A slight decrease in calf circumference <1 cm was seen in the ten ankles, 1-2 cm in the four ankles. Nine ankles were mildly hypersensitive to meteorological changes. Peak torque of ankle plantar flexion was slightly lower on the index limb at both velocities in nine selected patients who carried out performance tests. However, there were no significant differences (5.2% at 30 degrees /s and 2.7% at 120 degrees /s, P = n.s. and P = n.s.). Of the 12 available follow-up magnetic resonance images, the average cross-sectional area of the remaining tendon was 82.01 mm(2) (range 69.05-107.35; SD 10.3), and their average thickness was 7.4 mm (range 6-10.35; SD 1.1). After a minimum 10-year follow-up, the harvesting of autogenous Achilles tendons was not found to significantly jeopardize ankle status. However, it also could not be independent of donor morbidity as an alternative. The level of evidence was retrospective level IV, as a therapeutic study.

Patella fracture during rehabilitation after bone-patellar tendon-bone anterior cruciate ligament reconstruction: 2 case reports

STUDY DESIGN

Case report.

BACKGROUND

Patellar fracture is a rare but significant complication following anterior cruciate ligament (ACL) reconstruction when using a bone-patellar tendon-bone (BPTB) autograft. The purpose of these case reports is to describe 2 cases in which patellar fracture occurred during rehabilitation after ACL reconstruction using a BPTB.

CASE DESCRIPTION

Both patients were 23-year-old males referred for rehabilitation after ACL reconstruction using a BPTB autograft. They were both progressing satisfactorily in rehabilitation until sustaining a fracture of the patella. One fracture occurred during the performance of the eccentric phase of a knee extension exercise during the sixth week of rehabilitation (7 weeks postsurgery), whereas the other fracture occurred during testing of the patient is quadriceps maximum voluntary isometric contraction in the ninth week of rehabilitation (10 weeks postsurgery). Both patients were subsequently treated with open reduction and internal fixation of the patella.

DISCUSSION

During rehabilitation following ACL reconstruction using BPTB autograft, clinicians should consider the need to balance the sometimes-competing goals of improving quadriceps strength while providing protection to the healing graft, minimization of patellofemoral pain, and protection of the patellar donor site.

Anterior cruciate ligament reconstruction: outcome using a patellar tendon bone (PTB) autograft (one bone block technique)

OBJECTIVE

The aim of this study was to determine the outcome of anterior cruciate ligament (ACL) reconstruction using a patellar tendon bone autograft (one bone block technique).

METHOD

We retrospectively evaluated a case series of patients who had received arthroscopic ACL reconstructions using patellar tendon bone autograft. Fifty-four (54) ACL reconstructions were evaluated at a mean of 38 months (range 25-62 months). Clinical assessment was made using a modified Lysholm score, documentation of International Kappanee Documentation Committee (lKappaDC), the anterior knee pain questionnaire of Shelbourne and Trumper, and by KappaTau-Rolimeter arthrometric analysis. Radiographic assessments were also performed.

RESULTS

Arthrometric analysis showed that 51 knees (94%) were graded Alpha or Beta with a median laxity of 2 mm, postoperatively. The Lysholm score improved postoperatively from 70 to 89. The patellar position in terms of congruence angle did not show any significant change, and the final shortening of the patellar tendon using the Insall-Salvati ratio was 6.07%. Only three patients complained of moderate pain on kneeling, one patient was unable to participate in strenuous works and one patient complained of harvest-site tenderness.

CONCLUSION

It is concluded that the use of patellar tendon autograft with a single tibial-tubercule bone block and a strip of patellar periosteum have the advantages of being available and comparable in terms of graft size and strength and shows satisfactory results with reduced anterior knee pain.

Patellofemoral osteoarthritis 15 years after anterior cruciate ligament injury--a prospective cohort study

OBJECTIVE

Prevalence and clinical relevance of patellofemoral (PF) osteoarthritis (OA) after anterior cruciate ligament (ACL) injury.

METHOD

Prospectively we studied 94 out of 100 consecutive patients 15 years after acute ACL injury. ACL reconstructions were only performed late if recurrent "give way" persisted or a secondary meniscal injury suitable for repair occurred. The subjects, mean age 42 years, had knee radiographs including skyline PF view taken, which were graded according to the atlas of the Osteoarthritis Research Society International. Knee-related symptoms and function were assessed by questionnaires.

RESULTS

PF OA was present in 12/75 knees (16%). Of 94 patients 22 (23%) have had their ACL reconstructed during follow-up. Meniscal injury and ACL reconstruction had occurred more often in knees with PF OA than in knees without PF OA (P=0.004 and P=0.002, respectively). Seven of 15 ACL reconstructed knees showed radiographic PF OA at follow-up. Knees with PF OA had more extension and flexion deficit than knees without PF OA. Subjects with PF OA maintained a higher activity level from injury to follow-up, but did not differ significantly from those without PF OA regarding patient-relevant symptoms and knee function. However, there was a trend for worse outcome in subjects with PF OA.

CONCLUSION

We found a relatively low prevalence of mild PF OA after ACL injury treated non-operatively, and it had limited impact on knee symptoms and patient-relevant knee function. At follow-up PF OA was associated with higher activity level, meniscal injury, extension and flexion deficit, and ACL reconstruction.

Isokinetic Dynamometry in Anterior Cruciate Ligament Injury and Reconstruction

The use of isokinetic dynamometry has often been criticised based on the face-validity argument that isokinetic movements poorly resemble the everyday multi-segmented, dynamic activities of human movements. In the anterior cruciate ligament (ACL) reconstruction or deficiency population where muscle deficits are ubiquitous, this review paper has made a case for using isokinetic dynamometry to isolate and quantify these deficits in a safe and controlled manner. More importantly, the usefulness of isokinetic dynamometry, as applied in individuals with ACL reconstruction or deficiency, is attested by its established known-group and convergent validity. Known-group validity is demonstrated by the extent to which a given isokinetic measure is able to identify individuals who could and could not resume pre-morbid athletic or strenuous activities with minimal functional limitations following an ACL injury. Convergent validity is demonstrated by the extent to which a given isokinetic measure closely associates with self-report measures of knee function in individuals with ACL reconstruction. A basic understanding of the measurement properties of isokinetic dynamometry will guide the clinicians in providing reasoned interventions and advancing the clinical care of their clients. Key words: Biomechanics, Knee, Validity

A meta-analysis of patellar tendon autograft versus patellar tendon allograft in anterior cruciate ligament reconstruction

PURPOSE

Studies have suggested good long-term success rates with bone-patellar tendon-bone (BPTB) autograft and BPTB allograft in anterior cruciate ligament (ACL) reconstruction, but the numbers reported in available prospective studies may be underpowered to elucidate significant differences between the two groups. Here, we present a meta-analysis to compare the results of BPTB autograft and BPTB allograft in primary ACL reconstruction.

METHODS

A systematic review of prospective trials using BPTB autograft and BPTB allograft tissue for ACL reconstruction with a minimum 2-year follow-up was performed. Summary odds ratios (ORs), confidence intervals, and P values were calculated.

RESULTS

Of 548 studies, 6 fulfilled our inclusion criteria, with 256 patients in the autograft and 278 patients in the allograft group. Allograft patients were more likely to rupture their graft than autograft patients (OR, 5.03; P = .01) and more likely to have a hop test less than 90% of the nonoperative side (OR, 5.66; P < .01). When irradiated and chemically processed grafts were excluded from analysis, no significant differences were found between allograft and autograft patients with respect to graft rupture, rate of reoperation, normal/near normal IKDC scores, Lachman exam, pivot shift exam, patellar crepitus, hop test, or return to sport.

CONCLUSIONS

In this meta-analysis, ACL reconstruction with BPTB autograft was favored over BPTB allograft for graft rupture and hop test parameters. However, when irradiated and chemically processed grafts were excluded, results were not significantly different between the two graft types.

LEVEL OF EVIDENCE

Level III, systematic review of prospective nonrandomized cohort studies.

Use of a bioscaffold to improve healing of a patellar tendon defect after graft harvest for ACL reconstruction: A study in rabbits

Following harvest of a bone-patellar tendon-bone (BPTB) autograft, the central third of the patellar tendon (PT) does not heal well. The healing tissues also form adhesions to the fat pad and can cause abnormal patellofemoral joint motion. The hypotheses were that a bioscaffold could enhance patellar tendon healing through contact guidance and chemotaxis, and the scaffold could serve as a barrier to decrease adhesion formation between the neo-PT and infrapatellar fat pad. In 20 New Zealand White rabbits, a central-third PT defect was created. One strip of porcine small intestinal submucosa (SIS) was attached to both the anterior and posterior sides of the PT defect of the SIS-treated group (n = 10). For comparison, a central defect was left nontreated (n = 10). At 12 weeks, histomorphology was examined using Masson's trichrome staining. The cross-sectional area (CSA) was determined with a laser micrometer, and the central BPTB complexes were tested in uniaxial tension. SIS-treated samples showed a greater amount of healing tissue with denser and well-oriented collagen fibers and more spindle-shaped cells. There was no noticeable adhesion formation in the SIS-treated group. For the nontreated group, there were significantly more and diffuse adhesive formations. The SIS-treated group also had a 68% increase in neo-PT CSA, 98% higher stiffness, and 113% higher ultimate load than that in the nontreated group. SIS treatment increased the quantity of healing tissue, improved the histological appearance and biomechanical properties of the neo-PT, and prevented adhesion formation between the PT and fat pad.

Clinical comparison of fixation methods for patellar bone quadriceps tendon autografts in anterior cruciate ligament reconstruction: absorbable cross-pins versus absorbable screws

BACKGROUND

Recently, the use of the quadriceps tendon transplant with bone block (patellar bone quadriceps tendon autografts) for anterior cruciate ligament reconstruction has increasingly been reported.

HYPOTHESIS

Clinical results after the implantation of a patellar bone quadriceps tendon autograft fixed with cross-pins or screws will show no significant difference between the 2 techniques with regard to stability, function, and subjective satisfaction.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Between 1998 and 2004, 193 patients with anterior cruciate ligament ruptures were implanted with a patellar bone quadriceps tendon autograft. For 100 of these patients, fixation was carried out using absorbable cross-pins, and for the remaining 93, fixation was carried out using absorbable screws. The results were evaluated by means of International Knee Documentation Committee, Noyes, and Lysholm scores, as well as KT-1000 arthrometer measurement and subjective satisfaction.

RESULTS

The mean follow-up postoperative control period was 29 months. In the International Knee Documentation Committee overall evaluation, the pin group showed a significantly better result (P =.03). The values of the Noyes score produced no significant differences. The mean value of the Lysholm score was 94 points in the screw group and 89 points in the pin group (P <.001). Overall, 90% of the patients subjectively judged their conditions as good or very good.

CONCLUSION

With both operating processes examined, 80% to 90% of the cases achieved good to very good results. The use of cross-pins can be recommended for fixing patellar bone quadriceps tendon autografts.

Clinical comparison of the autologous quadriceps tendon (BQT) and the autologous patella tendon (BPTB) for the reconstruction of the anterior cruciate ligament

The use of the BPTB-autograft is a very common method for ACL reconstruction. Nevertheless, the problem of the typical donor-site-morbidity is unresolved. Recently, a transplant of quadriceps tendon, with an attached bone block (BQT) has been increasingly relied upon. The purpose of this study was to examine the clinical results of a group of patients after arthroscopic ACL reconstruction using either BPTB or quadriceps tendon autograft after a minimum follow-up of 2 years in terms of knee joint stability and function using both subjective and objective criteria. Retrospective study. A total of 260 patients with ACL ruptures were operated between 1995 and 2000; 124 received a BQT-autograft, including 8 revisions; 136 patients received a BPTB-autograft, exclusively primary interventions. The results were evaluated using the IKDC-, Noyes- and Lysholm-Scores. It was possible to re-evaluate 194 patients after a minimum follow-up period of 2 years, 64 of 260 patients (25%) were lost to follow-up. Ninety-seven percent of the operated knee joints in the BPTB-group were judged as normal or almost normal with the IKDC evaluation, as were 83% in the BQT-group (P < or = 0.001). The BQT-group showed a significantly better result in the evaluation of the donor-site-morbidity. We found no significant differences in the functional outcome according to the Lysholm- and Noyes-Score. In comparison to the results after using a BQT-transplant for reconstruction of a ruptured ACL the use of the BPTB-transplant is in favour concerning patient satisfaction and IKDC evaluation. For patients with activities involving kneeling or prolonged flexion of the knee joint BQT-transplants can be a good alternative, however.

Patellar tendon length after anterior cruciate ligament reconstruction: a comparative magnetic resonance imaging study between patellar and hamstring tendon autografts

Patellar tendon shortening after anterior cruciate ligament reconstruction may be associated with anterior knee pain or patellofemoral arthritis. The present study was designed to compare postoperative changes in patellar tendon length after anterior cruciate ligament reconstruction between patellar tendon and hamstring tendon autograft. Magnetic resonance images of both knees (operated and healthy) and functional outcome were documented at least 1 year postoperatively in 16 patellar tendon harvested patients and in 32 hamstrings harvested patients. Patellar tendon length, patella length and Insall-Salvati ratio were measured. The operated knee values were compared to the respective values of the non-operated control knees. A significant 4.2 mm or 9.7% patellar tendon shortening in patellar tendon group and a non-significant 1.14 mm or 2.6% shortening in hamstrings group was detected. No significant difference was detected in terms of major shortening-patella baja-(6% for the patellar tendon group vs. 0% for the hamstring group). There was no significant difference in anterior knee problems between the two groups as evidenced by the Shelbourne score (94 for the patellar tendon group vs. 98 for the hamstring group). Harvesting of the patellar tendon for anterior cruciate ligament reconstruction resulted in a significant shortening of the remaining tendon. In contrast harvesting of the hamstring tendons did not affect significantly the patellar tendon length. However, the incidence of patella baja and overall functional outcome was not significantly different between the two groups.

Prospective randomized clinical comparison of femoral transfixation versus bioscrew fixation in hamstring tendon ACL reconstruction--a preliminary report

PURPOSE

The purpose of this study is to clinically evaluate hamstring tendon anterior cruciate ligament (ACL)-reconstruction using femoral fixation with bioresorbable interference screws and with a bioresorbable transfixation device.

HYPOTHESIS

The ACL-reconstruction using the transfixation device at the femoral side leads to less knee laxity and therefore to a better clinical outcome for the patient.

TYPE OF STUDY

Prospective randomized clinical outcome study.

METHODS

From February 2002 to December 2002, a total of 68 patients with hamstring ACL reconstruction using a femoral fixation once with TransFix (n=38; m:22 and f:16; median age=28.5 range 15-47) and the second with bioscrew (BS) (n=30; m:20, f:10; median age=25.5 range 13-61) completed the follow-up period. Patients in each group got a clinical assessment at 3, 6, and 12 months after surgery. The measurement of anterior translation of the tibia has been performed using the Rolimeter device.

RESULTS

No significant differences in the knee laxity testing using the Rolimeter device were seen between both groups and over time within these groups. Ninety percent of all patients had functionally normal or near normal International Knee Documentation Committee (IKDC) knee ligament ratings. The TF-group included 17 grade A, 19 grade B, and 2 grade C knees, and the BS-group had 12 grade A, 13 grade B, and 5 grade C knees. The IKDC rating, the OAK-score, the Tegner-activity-score, and the Lysholm-score did not show significant differences between the TF-group and the BS-group.

CONCLUSION

We disproved our hypothesis that the transfixation technique leads to less laxity and therefore to a better clinical outcome when compared to the use of BS. The clinical results in this study clarified that this technique is an effective and safe method for femoral hamstring fixation in ACL-reconstruction. However, this technique revealed no advantage compared to the bioscrew fixation technique within the short-term follow-up.

Clinical comparison of the Tutoplast allograft and autologous patellar tendon (bone-patellar tendon-bone) for the reconstruction of the anterior cruciate ligament: 2- and 6-year results

BACKGROUND

The use of an allograft as a suitable transplant is still open to debate, in terms of donor morbidity, implantation reaction, and long-term results, as well as the risk of disease transmission.

HYPOTHESIS

The clinical results 2 and 6 years after implantation of a bone-patellar tendon-bone allograft (Tutoplast) and bone-patellar tendon-bone autograft show no significant difference in relation to stability, function, and rate of rupture.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHOD

Between 1995 and 1998, 268 patients with anterior cruciate ligament ruptures were surgically treated: 132 patients received a bone-patellar tendon-bone allograft implantation and 136 patients a bone-patellar tendon-bone autograft. The results were evaluated using the International Knee Documentation Committee, Noyes, and Lysholm scores.

RESULTS

There were 201 patients assessable after 2 years and 186 patients after 6 years. Ruptures of the implants in the allograft group occurred in 20 patients (20.6%) within 2 years and in 38 patients (44.7%) after 6 years. In the autograft group, transplants ruptured in 5 patients (4.8%) after 2 years and in 6 patients (5.9%) after 6 years.

CONCLUSION

Based on the data, it would appear that the regular use of bone-patellar tendon-bone allografts, particularly for physically active patients, is unsuitable.

A model of soft-tissue graft anterior cruciate ligament reconstruction in sheep

INTRODUCTION

Since there is to our knowledge no clinically valid and reproducible animal model of soft-tissue anterior cruciate ligament (ACL) reconstruction currently available, we developed one in sheep, in terms of graft suitability, postsurgical recovery, and knee stability.

MATERIALS AND METHODS

To find a suitable graft, anatomical dissections of the hind limbs of 7 sheep were performed. After a pilot study in 3 sheep, we reconstructed the ACL with an ipsilateral, longitudinally split, superficial digital flexor tendon autograft and anatomic graft fixation in 42 sheep (study 1) and with a full, superficial digital flexor tendon autograft and extracortical graft fixation in 48 sheep (study 2). Follow-up examinations ranged from 6 to 104 weeks (study 1) and 3 to 24 weeks (study 2).

RESULTS

All animals tolerated the graft harvest well and returned to physiological movement after about 4 weeks. Only 1 out of 93 ACL reconstructions failed. At final follow-up, the anteroposterior (AP) drawer displacement in both studies had almost regained the value of the intact contralateral knee. Maximum load-to-failure improved over time in both studies but was significantly lower at all time points compared with the intact ACL and the graft tissues. Tensile stress was significantly lower at final follow-up in both studies compared with the intact ACL and graft tissues. It attained 43.3% of the intact ACL and 58.3% of the graft tissue in study 1 and 28.9% and 22.8% in study 2, respectively.

CONCLUSION

The flexor tendon is suitable, and sheep appear to be an appropriate animal model for soft-tissue graft ACL reconstruction. They tolerate the graft harvest well and quickly return to full weight-bearing and physiological movement. Their knees become stable without showing signs of macroscopically evident osteoarthritis.

Donor site morbidity and return to the preinjury activity level after anterior cruciate ligament reconstruction using ipsilateral and contralateral patellar tendon autograft: a retrospective, nonrandomized study

AIM

To compare the donor site morbidity after anterior cruciate ligament reconstruction using ipsilateral and contralateral bone-patellar tendon autograft.

STUDY DESIGN

Cohort study; Level of evidence, 2 PATIENTS AND METHOD: Between 1997 and 1999, 100 patients underwent anterior cruciate ligament reconstruction with autologous bone-patellar tendon graft. The reconstructions were performed using ipsilateral bone-patellar tendon graft in 52 patients (group Ip) and contralateral bone-patellar tendon graft in 48 patients (group Co). Group Co consisted of 2 subgroups: group CoD consisted of the donor knees (n=48) and group Co-ACL consisted of the anterior cruciate ligament-reconstructed knees (n=48). Mean follow-up was 39.2 months. Donor site morbidity was evaluated with a questionnaire, computerized historical data, KT-2000 arthrometer measurements, the Cincinnati score, and the Tegner score.

RESULTS

KT-2000 arthrometer evaluation showed a mean side-to-side difference of 0.6 mm in both groups. There were no significant differences between the 2 groups concerning the Cincinnati and Tegner scores. With regard to local tenderness, a significantly higher rate was found in group Ip (59.6%) and group Co-D (58.3%) compared with group Co-ACL (6.3%). In groups Ip and Co-D, high statistically significant differences were also found according to kneeling pain (69.2% and 70.8%, respectively) and knee-walking pain (76.9% and 70.8%, respectively) compared with group Co-ACL (6.3% and 10.4%, respectively). With regard to numbness, there was no statistical significance between the rates of all 3 groups: group Ip=75%, group Co-D=85.4%, and group Co-ACL=64.6%. There was one rupture of the patellar tendon and one patient with chronic patellar tendinitis, both in the donor knee of group Co-D.

CONCLUSION

The contralateral bone-patellar tendon graft appears to present no advantage over the ipsilateral graft, as all symptoms concerning donor site morbidity are shifted from the injured into the healthy knee, and return to activity is not more rapid.

[Pain after anterior cruciate ligament reconstruction: detail and treatment]

OBJECTIVE

Several factors can influence the occurrence of pain after anterior cruciate ligament (ACL) ligamentoplasty, namely, factors linked to the selection of graft, the surgical technique and rehabilitation program. The aim of this research was to review the literature for different types of pain experienced after ACL reconstruction to illuminate better prevention and treatment.

METHOD

We reviewed reports by searching the PUBMED* research engine using the key words pain, complication, and anterior cruciate ligament.

RESULTS

We found an increasing incidence of anterior pain after use of the patellar tendon for ACL reconstruction. Some anterior pain can be mistakenly interpreted as donor site morbidity or patello-femoral problems, but it is in fact linked to graft impingement caused by bad placement of tunnels and/or proliferation of a fibrovascular nodule on the ACL graft ("cyclops syndrome"). Some posterior-external pain, sometimes associated, can occur under the same circumstances. Cartilage, ligament or meniscal lesions or saphenous nerve injuries can explain some occurrences of pain. Pain linked to loco-regional factors such as reflex sympathetic dystrophy appear to be rare with rehabilitation and surgery.

CONCLUSION

The treatment of pain after ACL reconstruction lies first in the establishment of an etiologic diagnosis. Prevention, by controlling tendon-muscular and joint stress during rehabilitation, is essential and requires sound knowledge of biomechanical data.

MRI evaluation of patellar tendon defect after harvesting its central third

PURPOSE

the purpose of this study was to evaluate defect width of patellar tendon after harvest for anterior cruciate ligament reconstruction.

MATERIALS AND METHODS

we performed MRI at various time interval after graft harvest (2-96 months) on 28 patients who had had reconstruction of the anterior cruciate ligament using mid-third patellar tendon. T1 and T2 weighted axial images were obtained to assess donor site defect of the patellar tendon. Measurement of the defect width was performed at the level of menisci on the axial images. The patients were divided into two groups according to the time interval between operation and imaging. The defect width of patients with short time interval (2-12 months) was compared to the defect width of patients with long time interval (12-96 months).

RESULTS

the average defect width of patients with short time interval was 6.4 mm and it was 2.2 mm for the patients with long time interval. Decreased defect width was obtained from MRI images in the patients with long time interval. Closed donor site defect was detected in 1 out of 14 patients with short time interval and 6 out of 14 patients with long time interval.

DISCUSSION AND CONCLUSION

these results show that there is no complete closure of donor site defect up to 1 year. However, it seems to be nearly complete closure of patellar tendon defect in the long time period.

Hamstring insertion site healing after anterior cruciate ligament reconstruction in patients with symptomatic hardware or repeat rupture: a histologic study in 12 patients

PURPOSE

Our goal was to characterize the type of biologic anchor of hamstring tendons to the femoral tunnel in cases of transfixion fixation for the anterior cruciate ligament (ACL) reconstruction. The histologic bone-hamstring tendon anchorage is not yet clearly understood despite many experimental and some clinical studies. It constitutes the weak point of the ACL reconstruction. The type of fixation, either distant from the joint such as transfixion fixation or at the tunnel entrance such as aperture fixation will determine a specific tendon-bone healing process.

TYPE OF STUDY

Histological study.

METHODS

We performed ACL reconstruction with 4 strands of semitendinosus and gracilis tendons fastened by a transfixion fixation. Femoral fixation was secured by transfixion (Transfix; Arthrex, Naples, CA) and tibia fixation by a biodegradable interference screw and 2 staples. Between 3 and 20 months after surgery, we performed 12 hamstring tendon biopsies (in 9 men and 3 women; mean age, 29 years). Biopsies were performed 2 cm from the femoral outlet in 10 patients undergoing hardware removal or by coring the femoral tunnel in 2 cases of repeat rupture. In 8 cases, the femoral device was removed for persistent lateral pain, in 2 cases for instability of the hardware, and in 2 cases a repeat rupture of the graft occurred. The samples were taken by coring a tunnel 5 mm in diameter, with a tubular harvester, along the femoral Transfix axis. Each fragment was stained with H&E, Solochrome cyanine, or Masson-trichrome, and microscopical examination was performed, including polarized light.

RESULTS

At 3 months (in 1 case), a fibrovascular interface was seen between the tendon and uncalcified osteoid with very few collagen fibers. At 5 and 6 months (in 2 cases), some Sharpey-like fibers and less immature woven bone was seen. Maturity of the secondary insertion was seen after at least 10 months in 5 cases. In 2 cases, no contact was seen at the biopsy site despite good clinical stability. The 2 remaining cases underwent repeat rupture at the midsubstance of the graft at 12 and 17 months after surgery. In the first case, the tendon-bone fixation was limited at the outlet of the femoral tunnel with no fixation inside the tunnel. In the second case, the fixation was continuous with Sharpey fibers along the tunnel.

CONCLUSIONS

According to our histologic results in patients, the time to obtain a mature indirect anchorage at the top of the tunnel was 10 to 12 months, which is much longer than in reported animal models (6 to 24 weeks). To our knowledge, this is the first clinical study reporting the histologic type of femoral ligament insertion 2 cm from the outlet of the tunnel with hamstring autograft for ACL reconstruction.

Anterior cruciate ligament reconstruction using semitendinosus and gracilis tendons, bone patellar tendon, or quadriceps tendon-graft with press-fit fixation without hardware. A new and innovative procedure

BONE--PATELLAR TENDON: The "no hardware" technique for ACL reconstruction is a new method that offers many advantages and is straightforward to perform. Its main innovative feature is that it does not require bone-block harvesting from the patella. This reduces donor site morbidity and prevents patellar fractures. The bone tunnels are made using tube harvesters and compaction drilling. This minimizes trauma and obviates the risk of bone necrosis. The articular entrance of the tibial tunnel is completely occupied by the grafts. This prevents a windshield-wiper effect and synovial fluid ingress into the tunnel, and enhances graft incorporation. The fact that no hardware is used with both patellar tendon or hamstring grafts significantly reduces the overall cost of the operation and facilitates revision surgery. The quadriceps tendon is also a very good graft. It is thick and has good biomechanical properties and low donor site morbidity. Its disadvantages are: weakness of quadriceps after the operation, an unsightly scar, and some difficulty in graft harvesting [58]. Also, postoperative MRI is not fraught with the problem of metal artifacts. It is difficult to decide which of the methods currently available for ACL reconstruction is the best because most of them give satisfactory results. In the future, assessments of knee ligament reconstruction techniques should look at long-term stability combined with low complication rates. Ease of revision surgery and low cost should also be taken into consideration, given the large annual volume of knee ligament reconstructions (50,000 in the United States alone) [59]. We believe that our technique addresses most of these issues, and that it constitutes a useful alternative method for ACL reconstruction. SEMITENDINOSUS--GRACILIS: This technique, which was used with 915 patients from June 1998 to February 2002, shows a particularly low rate of postoperative morbidity. The reason is probably to be found in the "waterproofing" of the bone tunnels, which lead to less postoperative bleeding and swelling. No drains were used. Rehabilitation follows the same protocol as used for the reconstruction using patellar tendon grafts (accelerated/functional). As expected, there was no widening of the femoral tunnels and little widening of the tibial tunnels. Interestingly, tibial tunnel enlargement was significantly less in a nonaccelarated rehabilitation group than in the accelerated group [60] without affecting stability. The measured internal torque of the hamstrings, as well as their flexion force, already had returned to normal 12 months postoperatively. In a prospective randomized (unpublished) study comparing this technique with ACL reconstruction with BPT grafts with medial or lateral third with only one bone plug (from the tibial tuberosity, see technique described above), we found no significant difference between both groups in subjective scores, stability, KT-1000 values, Tegner activity score, and IKDC at 1-year follow-up. Only the results of kneeling and knee walking testing were significantly better in the hamstring group [61]. In summary, the advantages of this presented technique are: (1) the knot of the graft is close proximally to the anatomic site of the insertion of the ACL, thus avoiding the Bungee effect.; (2) the press-fit tunnel fixation prevents synovial fluid entering the bone tunnels, windshield-wiper effect, and longitudinal motion within the tunnel; the intensive contact between the bony wall of the tunnel and graft collagen over a long distance without any suture material results in quick and complete graft incorporation; and (3) no fixation material means no hardware problems, facilitates revision surgery, and lowers overall costs.

The effect of graft stiffness on knee joint biomechanics after ACL reconstruction--a 3D computational simulation

OBJECTIVE

The objective was to determine the effect of varying graft stiffness and initial graft tension on knee kinematics and graft tension after anterior cruciate ligament reconstruction.

DESIGN

A 3D computational knee model was used.

BACKGROUND

Many factors influencing the biomechanical outcome of anterior cruciate ligament reconstruction have been investigated. However, there are no reports on the effect of variations in graft stiffness on knee behavior.

METHODS

A 3D computational knee model was used to simulate anterior cruciate ligament reconstruction using three different grafts with stiffnesses similar to the anterior cruciate ligament (graft 1), a 10mm bone-patellar tendon-bone graft (graft 2), and a 14 mm bone-patellar tendon-bone graft (graft 3). The initial graft tension was set to 0 or 40 N with the knee at 30 degrees of flexion. A 134 N anterior tibial drawer load and a 400 N quadriceps load were applied to the knee, and kinematics and graft tension were calculated.

RESULTS

When fixed with no initial tension, graft 1 was found to under-constrain the knee, while graft 2 slightly over-constrained the knee, and graft 3 over-constrained the knee when compared to the intact knee. When an initial graft tension of 40 N was used, all of the reconstructed knees were more constrained than when an initial tension of 0 N was used.

CONCLUSIONS

This study suggests that graft stiffness has a direct impact on knee biomechanics after anterior cruciate ligament reconstruction. An optimal anterior cruciate ligament reconstruction can be achieved if the anterior cruciate ligament is replaced by a graft with similar structural stiffness.

RELEVANCE

This study showed that if the graft material and fixation sites are selected such that the anterior cruciate ligament structural stiffness is retained, normal knee kinematics can be restored.

Anterior cruciate ligament reconstruction utilizing central quadriceps free tendon

CQFT ACL reconstruction yields a stable, highly functional knee with little associated morbidity. Patient satisfaction has been very high, and objective follow-up data collected thus far is very encouraging.

Length of the patellar tendon after anterior cruciate ligament reconstruction with patellar tendon autograft: a prospective clinical study using Roentgen stereometric analysis

PURPOSE

This prospective study was designed to assess postoperative changes in patellar tendon length after removal of its central one third for anterior cruciate ligament (ACL) reconstruction using precise Roengen stereometric analysis (RSA).

TYPE OF STUDY

Prospective clinical study.

METHODS

Ten consecutive patients underwent arthroscopically assisted ACL reconstruction using the mid-third bone-patellar tendon-bone (BPTB) autograft. The tendon defect was left open and the paratenon was approximated with sutures. Tantalum beads were inserted in the distal part of the patella and in the tibial tuberosity through the bone defects. The distance between the tantalum markers in the patella and the tibial tuberosity was measured with RSA at the first day and at 1, 2, 3, 6, and 12 months after surgery.

RESULTS

A decrease of patellar tendon length was observed in all cases. The amount of shortening averaged 1.6 mm (range, 0.5 to 3.2 mm), 3.2% of the initial length. In 4 patients, tendon shortening was detected during the first 4 weeks after surgery. In 6 cases, decrease of patellar tendon length started between the fourth and the eighth week. The shortening process continued in 8 knees until the 12th week. No further changes in patellar tendon length were observed after the 12th postoperative week. In 2 patients, shortening of the patella tendon exceeded 2 mm. The amount of patellar tendon shortening was not related to anterior knee pain.

CONCLUSIONS

After removing the BPTB autograft, irreversible shortening of the remaining two thirds of the patellar tendon occurred during the first 12 postoperative weeks.