Outcome and risk factors after anterior cruciate ligament reconstruction: a follow-up study of 948 patients

Second-look arthroscopic findings and clinical results after polyethylene terephthalate augmented anterior cruciate ligament reconstruction

PURPOSE

Based on the revival of artificial ligaments containing polyethylene terephthalate, this study aimed to evaluate objective intra-articular findings within scheduled second-look arthroscopy, patient-reported clinical outcome and stability after isolated augmented ACL reconstruction with polyethylene terephthalate (Trevira®) augmented patella-bone-tendon-bone graft.

METHODS

In a retrospective analysis of our institutional database, we found 126 patients with polyethylene terephthalate (Trevira®) augmented ACL reconstruction. All these patients underwent standardised second-look arthroscopic evaluation when removal of the augmentation became necessary. These second-look arthroscopic analyses focused on graft integration and remodelling in line with the polyethylene terephthalate augmentation. Arthroscopic re-examination comprised a graft evaluation including a structural and functional classification according to the Marburger Arthroscopy Score (MAS). Additional clinical evaluation was performed via the IKDC score and the scores of Tegner and Lysholm. Instrumental anterior laxity testing was carried out with a KT-1000™ arthrometer. Furthermore, a correlation analysis between the clinical parameters, the instrumental stability assessment and the corresponding arthroscopic graft condition was performed.

RESULTS

The arthroscopic evaluation showed rupture of 87 (69 %) of 126 augmentation devices. In 27 (31 %) of these 87 cases, synovial reactions were found particularly in the anterior compartment. An intact synthetic augmentation with signs of graft integration with intact synovial coating was only found in 30 %. Evaluation according to the MAS showed good to excellent structural and functional characteristics in 88 % of patients. Presence of a type III graft (MAS) was found in an additional 11 %. A rudimentary (type IV) graft was only detected once. Eighty-five percent of patients were graded A or B according to IKDC score. The Lysholm score was 92.4 ± 4.8. Correlation analysis demonstrated a significant relationship between clinical outcome according to the IKDC score (p<0.05), instrumental stability performance according to the KT-1000™ assessment (p<0.05) and the corresponding arthroscopic graft evaluation according to the MAS.

CONCLUSION

Graft integration and remodelling has complex and multi-factorial origins, particularly with artificial augmentation. Correlation analysis showed a significant relation between clinical condition, instrumental stability performance and arthroscopic graft constitution. The release of polyethylene terephthalate fibres caused inflammation of synovial tissue of the knee. Characteristic sub-clinical graft changes of structural, morphological and functional qualities of the inserted graft appear on second-look arthroscopy despite good clinical results.

Clinical outcome and prevalence of osteoarthritis after isolated anterior cruciate ligament reconstruction using hamstring graft: follow-up after two and ten years

PURPOSE

The aim of this study was to evaluate patient-reported clinical outcome, instrumental stability and prevalence of radiological osteoarthritis (OA) based on a homogeneous patient sample after two years and on average ten years after isolated anterior cruciate ligament (ACL) reconstruction.

METHODS

Primarily we performed ACL reconstruction using a four-strand semitendinosus tendon (ST) autograft in 112 patients. Two years after reconstruction 98 patients could be re-evaluated. Long-term clinical and functional follow-up assessment was then performed on 52 patients on average 10.2 years after operative treatment. Inclusion criteria consisted of an isolated ACL rupture, reconstruction with ST graft and no associated cartilage alterations and meniscal lesions. Clinical and functional follow-up assessment included the International Knee Documentation Committee (IKDC) score and the scores of Tegner and Lysholm. Instrumental stability testing was carried out with the KT1000™ arthrometer. The degree of degenerative changes and prevalence of OA was based on the Jäger-Wirth score.

RESULTS

The mean long-term follow-up was 10.2 years (eight-13 years), and the mean age was 40.4 years (24-62 years). About 72 % of patients were graded A or B according to the IKDC score. Activity levels according to the scores of Tegner and Lysholm were 4.8 and 88.2 on long-term follow-up. Radiological assessment revealed degenerative changes in the sense of a grade I OA in 21.2 % of patients. Prevalence of a grade II OA was found in 53.8 % of patients. A grade III OA and a grade IV OA were found in 19.2 and 5.7 %. Correlation analysis showed significant relationships between the long-term stability and prevalence of OA (p<0.05).

CONCLUSIONS

Arthroscopic ACL reconstruction using four-strand ST autograft resulted in high patient satisfaction and good clinical results at two years and long-term follow-up. The prevalence of higher degree OA that developed in about 25 % of patients is significantly correlated with long-term knee joint stability.

The outcome at 15 years of endoscopic anterior cruciate ligament reconstruction using hamstring tendon autograft for 'isolated' anterior cruciate ligament rupture

The purpose of this study was to report the outcome of 'isolated' anterior cruciate ligament (ACL) ruptures treated with anatomical endoscopic reconstruction using hamstring tendon autograft at a mean of 15 years (14.25 to 16.9). A total of 100 consecutive men and 100 consecutive women with 'isolated' ACL rupture underwent four-strand hamstring tendon reconstruction with anteromedial portal femoral tunnel drilling and interference screw fixation by a single surgeon. Details were recorded pre-operatively and at one, two, seven and 15 years post-operatively. Outcomes included clinical examination, subjective and objective scoring systems, and radiological assessment. At 15 years only eight of 118 patients (7%) had moderate or severe osteo-arthritic changes (International Knee Documentation Committee Grades C and D), and 79 of 152 patients (52%) still performed very strenuous activities. Overall graft survival at 15 years was 83% (1.1% failure per year). Patients aged < 18 years at the time of surgery and patients with > 2 mm of laxity at one year had a threefold increase in the risk of suffering a rupture of the graft (p = 0.002 and p = 0.001, respectively). There was no increase in laxity of the graft over time. ACL reconstructive surgery in patients with an 'isolated' rupture using this technique shows good results 15 years post-operatively with respect to ligamentous stability, objective and subjective outcomes, and does not appear to cause osteoarthritis.

Anterior cruciate ligament tears: conservative or surgical treatment? A critical review of the literature

PURPOSE

Is it rational to recommend surgical reconstruction of the torn anterior cruciate ligament to every patient? Is conservative management still a valid option?

METHOD

Through a literature review, we looked for the arguments from each side and checked their validity.

RESULTS

Unfortunately results of most studies cannot be compared because of the following reasons not exhaustively cited: studied populations differed with respect to age, sex, professional and sports activity level, lesions associated with ACL rupture, patient recruitment methods, time from injury to treatment and different therapeutic modalities. Furthermore, various methods were used to evaluate the clinical and radiological results and there was no consensus of their interpretation. Some authors assumed that the incidence of further meniscus lesions could probably be reduced if the torn ACL was surgically reconstructed. But, we have no evidence to believe that this would be due to the surgical repair rather than to a decrease of involvement in strenuous activities. At present it is not demonstrated that ACL-plasty can prevent osteoarthritis. Numerous factors could explain evolution to arthrosis whatever the treatment for the ACL-ruptured knee. Studies comparing surgical and conservative treatments confirm that ACL reconstruction is not the pre-requisite for returning to sporting activities. More recent and scientifically well-designed studies demonstrate that conservative treatment could give satisfactory results for many patients. They suggest some methods to help them choose the best treatment.

CONCLUSION

At present there are no evidence-based arguments to recommend a systematic surgical reconstruction to any patient who tore his ACL. Knee stability can be improved not only by surgery but also by neuromuscular rehabilitation. Whatever the treatment, fully normal knee kinematics are not restored. While the patients wish to go back to their sport and want everything possible done to prolong their ability to perform these activities, they should be informed that the risk of further knee lesions and osteoarthritis remains high, whatever the treatment, surgical or conservative.

LEVEL OF EVIDENCE

Systematic review of Level I, II, III and IV studies, Level IV.

Knee function and prevalence of osteoarthritis after isolated anterior cruciate ligament reconstruction using bone-patellar tendon-bone graft: long-term follow-up

PURPOSE

The aim of this investigation was to study patient-reported long-term clinical outcome, instrumental stablitity and prevalence of radiological osteoarthritis (OA) a minimum of ten years after isolated anterior cruciate ligament (ACL) reconstruction.

METHODS

An average of 13.5 years after ACL reconstruction with bone-patellar tendon-bone (BTB) autograft, 73 patients were evaluated. Inclusion criteria consisted of an isolated ACL rupture and reconstruction with BPTB graft with no associated intra-articular lesions, in particular, cartilage alterations or meniscal lesions. Clinical assessment was performed using the International Knee Documentation Committee (IKDC) and Tegner and Lysholm scores. Instrumental anterior laxity testing was carried out with the KT-1000™ arthrometer. Degree of degenerative changes and prevalence of OA were determined using the Kellgren- Lawrence scale.

RESULTS

Mean follow-up was 13.5 years. Mean age was 43.8 years. About 75% of patients were graded A or B according to the IKDC score. The Lysholm score was 90.2 ± 4.8. Radiological assessment reported degenerative changes of grade II OA in 54.2% of patients. Prevalence of grades III or IV OA was found in 20%. The incidence of OA was significantly correlated with stability and function at long-term follow-up.

CONCLUSION

Arthroscopic ACL reconstruction using BPTB autograft resulted in a high degree of patient satisfaction and good clinical results on long-term follow-up. A higher degree of OA developed in 20% of patients and was significantly correlated with increased anterior laxity at long-term follow-up.

Anterior cruciate ligament reconstruction using remnant preservation and a femoral tensioning technique: clinical and magnetic resonance imaging results

PURPOSE

The purpose of this study was to investigate the clinical and magnetic resonance imaging (MRI) results of anterior cruciate ligament (ACL) reconstruction with autogenous hamstring tendon by use of remnant preservation and a femoral tensioning technique.

METHODS

A total of 53 patients who had ACL reconstruction by use of remnant ACL stump preservation and a femoral tensioning technique were evaluated. Clinical evaluation at a minimum of 2 years after surgery included range of motion, Lachman test, pivot-shift test, KT-2000 arthrometer testing (MEDmetric, San Diego, CA), and clinical scores. Plain radiographs were evaluated for tunnel enlargement. MRI was obtained for evaluation of graft continuity, cyclops-like mass lesion, and positioning of the tibial tunnel. Second-look arthroscopy was performed in 33 patients.

RESULTS

The clinical scores improved postoperatively. There were statistically significant differences between preoperative and postoperative Lachman tests, pivot-shift tests, and KT-2000 arthrometer measurements. Postoperative MRI was available in 48 patients, and it showed intact graft in 45 patients, 2 partial tears, and 1 complete loss of graft. There were cyclops-like mass lesions in 12 patients, but none showed an extension limitation or pain at extension. The position of the tibial tunnel on the sagittal and coronal view was similar to the position of the normal ACL tibial insertion. The measured tibial tunnel widening on the radiographs at final follow-up was 2.2 ± 1.5 mm.

CONCLUSIONS

Reconstruction of the ACL by use of preservation and femoral tensioning of the remnant tissue showed good clinical results without increased concerns regarding incorrect tunnel formation. Postoperative MRI showed an increased incidence of cyclops-like mass lesions, but no clinical significance was observed.

LEVEL OF EVIDENCE

Level IV, case series.

Extracellular matrix content of ruptured anterior cruciate ligament tissue

Anterior cruciate ligaments (ACLs) can rupture with simple movements, suggesting that structural changes in the ligament may reduce the loading capacity of the ligament. We aimed to investigate if proteoglycan and collagen levels were different between ruptured and non-ruptured ACLs. We also compared changes in ruptured tissue over time. During arthroscopic knee reconstruction surgery 24 ruptured ACLs were collected from participants (10 females; 14 males; mean age 24 years). Four non-ruptured ACLs were obtained from participants undergoing total knee replacement surgery (one female, three males; mean age 66 years). Western blot analysis was used to characterise core proteins of aggrecan, versican, decorin and biglycan and glycosaminoglycan assays were also conducted. Collagen levels were measured by hydroxyproline (OHPr) assays. Significantly lower levels of collagen, were found in ruptured ACL compared to non-ruptured ACL (p=0.004). Lower levels of both small and large proteoglycans were found in ruptured than non-ruptured ACLs. No correlation was found between time since rupture and proteoglycan or collagen levels. Ruptured ACLs had less collagen and proteoglycans than non-ruptured ACLs. These changes indicate either extracellular matrix protein levels were reduced prior to rupture or levels decreased immediately after rupture. It is possible that the composition and structure of ACLs that rupture are different to normal ACLs, potentially reducing the tissue's ability to withstand loading. An enhanced understanding of the aetiology of ACL injury could help identify individuals who may be predisposed to rupture.

Functional outcome in athletes at five years of arthroscopic anterior cruciate ligament reconstruction

Introduction. The purpose of this study was to analyze the functional outcome in competitive level athletes at 5 years after ACL reconstruction with regard to return to sports and the factors or reasons in those who either stopped sports or showed a fall in their sporting levels. Methods. 48 competitive athletes who had undergone arthroscopic assisted ACL reconstruction with a minimum follow up of at least 5 years were successfully recalled and were analyzed. Results. 22 patients had returned to the preinjury levels of sports and 18 showed a decrease in their sporting levels. Of the 18 patients, 12 referred to fear of reinjuring the same or contra-lateral knee as the prime reason for the same while 6 patients reported persisting knee pain and instability as reasons for a fall in their sporting abilities. The difference in the scores of these groups was statistically significant. 8 patients out of the 48 had left sports completely due to reasons other than sports, even though they had good knee outcome scores. Conclusion. Fear of reinjury and psychosocial issues that are relevant to the social milieu of the athlete are very important and affect the overall results of the surgery with respect to return to sports.

Physiotherapy-guided versus home-based, unsupervised rehabilitation in isolated anterior cruciate injuries following surgical reconstruction

PURPOSE

The aim of this study was to investigate the outcome after ACL reconstruction between a group of patients receiving a standardized, supervised, physiotherapy-guided rehabilitation programme and a group of patients who followed an unsupervised, home-based rehabilitation programme.

METHODS

Forty patients with isolated anterior cruciate ligament injuries were allocated to either a supervised physiotherapy intervention group or home-based exercise group. Patients were investigated by an independent examiner pre-operative, 3, 6, 9 and 12 months post-surgery using the following outcome measures: Lysholm Score and Tegner Activity Scale, functional hopping tests, and isometric and isokinetic strength assessments.

RESULTS

Both groups improved significantly (P = 0.01-0.04) following 12 months after surgery. The median Lysholm score increased from 57 (34-90) to 94 (90-100) in the supervised group and 60 (41-87) to 97 (95-100) in the unsupervised group. The median Tegner Activity Scale increased from 3 (2-8) to 6 (3-8) in the supervised group and 4 (2-8) to 5 (3-10) in the unsupervised group. The combined mean symmetry indices for the hopping tests improved from 77.3 ± 18.7 to 86.8 ± 11.1 (supervised) and from 78.1 ± 30.5 to 88.3 ± 10.9 (unsupervised). Isometric and isokinetic strength symmetry indices for knee extension improved from 68.9 ± 23.5 to 82.8 ± 11.9, respectively, 63.7 + 22.8 to 82.7 + 15.1 in the supervised group and from 73.6 ± 20.5 to 76.5 ± 17.9, respectively, 69.5 ± 24.3 to 76.9 ± 16.9 in the unsupervised group. Eccentric strength symmetry indices for knee extension improved from 67.9 ± 27.7 to 87.8 ± 6.8 in the supervised group and from 71.3 ± 17.8 to 82.6 ± 15.6 in the unsupervised group.

CONCLUSION

This study could not demonstrate a benefit in a rehabilitation programme supervised by a physiotherapist in our population compared to an unsupervised cohort.

Activity profile of members of an online health community after articular cartilage repair of the knee

BACKGROUND

Articular cartilage repair (ACR) procedures aim to alleviate pain and restore function for individuals with chondral defects. Rehabilitation is lengthy, and there are limited data on return to sports and exercise activities after ACR in non-elite-athlete populations. The Internet is a growing source of health-related information for patients, and it has resulted in the emergence of online health communities.

PURPOSE

To establish a postoperative activity profile of users of an online health community who have undergone ACR of the knee and to compare this profile with those from the same community who have undergone initial anterior cruciate ligament reconstruction (ACLR).

STUDY DESIGN

Cross-sectional.

METHODS

Tegner Activity Scale ratings were collected via a self-reported online questionnaire from 201 participants of an online health community who had undergone tibiofemoral and/or patellofemoral ACR (n = 75) or ACLR (n = 126).

RESULTS

A higher Tegner activity level was significantly correlated to time from surgery for ACR (P < 0.005) and ACLR (P < 0.01). At a minimum of 24 months' follow-up, the ACR group had a median postoperative Tegner score of 3, compared with 6 for the ACLR group. Tegner score was significantly negatively correlated with age at time of surgery for ACLR (P < 0.05) but not for ACR. Men demonstrated significantly higher Tegner activity levels than did women for both ACLR and ACR (P < 0.05).

CONCLUSIONS

Activity levels after ACR in this population increased with postoperative time but remained lower than expected when compared with current published clinical and normative data.

CLINICAL RELEVANCE

Engagement with an online health community may influence expectations regarding return to sports and exercise activities. Reporting of activity-level data within clinical studies should be differentiated on the basis of sex. Further research is needed to elucidate factors that determine return to sports and exercise activities after ACR.

Health-related quality of life after anterior cruciate ligament reconstruction

PURPOSE

Recently the patients' own evaluation has become an important complement to post-operative clinical assessments. For many patients, there is a change in life situation after an anterior cruciate ligament reconstruction (ACL), which may affect the health-related quality of life in many ways. The aims of the study were to evaluate the results in terms of health-related quality of life 2-7 years after an ACL reconstruction and to compare the results with a gender- and age-matched control group. Furthermore, to compare the results for males and females using either the bone-patellar tendon-bone autograft (BPTB) or hamstring tendon autograft (HT).

METHODS

The SF-36 questionnaire was send by mail to 793 consecutive patients after an ACL reconstruction. Five hundred and forty-four (69%) patients returned the questionnaires leaving 419 patients (161 female, 258 male) who were analysed and matched to a Swedish control group (n = 2,410).

RESULTS

The patient group obtained significantly higher scores for General Health (GH), Social Function (SF), Role Emotional (RE) and Mental Health (MH). The control group obtained significantly higher scores for Physical Function (PF) compared with the total ACL group and with the BPTB and HS subgroups. There were no significant differences between males and females.

CONCLUSION

After ACL reconstruction, the patients reported good health-related quality of life in comparison with a matched sample of the general population. To incorporate non-disease-specific health assessment measures are important to further refine the disease-specific outcome measurements to evaluate the effect of the treatments and provide cost-effective treatment algorithms.

The prognosis and predictors of sports function and activity at minimum 6 years after anterior cruciate ligament reconstruction: a population cohort study

BACKGROUND

The predictors of anterior cruciate ligament reconstruction (ACLR) outcome at 6 years as measured by validated patient-based outcome instruments are unknown.

HYPOTHESIS

Certain variables evaluated at the time of ACLR will predict return to sports function (as measured by the International Knee Documentation Committee [IKDC] questionnaire and the Knee injury and Osteoarthritis Outcome Score [KOOS] Sports and Recreation subscale), knee-related quality of life (KOOS Knee Related Quality of Life subscale), and activity level (Marx Activity Scale). Potential predictor variables include demographic factors, surgical technique and graft choice for ACLR, and intra-articular injuries and treatment.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

All patients with unilateral ACLRs from 2002 currently enrolled in the MOON (Multicenter Orthopaedic Outcomes Network) cohort were evaluated. Patients completed the validated outcome instruments preoperatively. Physicians documented intra-articular pathologic abnormalities, treatment, and surgical techniques used at the time of surgery. At 2 and 6 years postoperatively, patients completed the same validated outcome instruments.

RESULTS

Follow-up was obtained at 2 years (88%) and at 6 years (84%). The cohort was 57% male with a median age of 23 years at enrollment. The ability to perform sports function was maintained at 6 years, but the Marx activity level continued to decline from baseline. Revision ACLR and use of allograft predicted worse outcomes on the IKDC and both KOOS subscales. Lateral meniscus treatment, smoking status, and body mass index at baseline were each predictors on 2 of 3 scales. The predictors of lower activity level were revision ACLR and female sex.

CONCLUSION

Six years after ACLR, patients could perform sports-related functions and maintain a high knee-related quality of life similar to their 2-year level, although their physical activity level (Marx) dropped over time. Choosing autograft rather than allograft, not smoking, and having normal body mass index are advised to improve long-term outcomes.

Fifteen-year outcome of endoscopic anterior cruciate ligament reconstruction with patellar tendon autograft for "isolated" anterior cruciate ligament tear

BACKGROUND

Few studies report the long-term results of anterior cruciate ligament rupture and single-incision endoscopic reconstructive surgery. Outcomes are often clouded by concomitant meniscal, chondral, or ligament injuries.

PURPOSE

To determine the 15-year outcomes of anterior cruciate ligament ruptures treated with endoscopic anterior cruciate ligament reconstruction using middle-third patellar tendon autograft.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between January 1993 and April 1994, 333 consecutive patients underwent anterior cruciate ligament reconstruction. Patients with associated ligamentous injury requiring surgery, previous meniscectomy, or meniscal injury requiring more than one-third meniscectomy; chondral injury diagnosed at arthroscopy; and an abnormal contralateral knee were excluded. Ninety patients met the inclusion criteria. Outcomes included range of motion, Lachman and pivot-shift tests, instrumented ligament testing, single-legged hop test, Lysholm Knee Score, the International Knee Documentation Committee evaluation, and radiographic assessment.

RESULTS

Thirty percent of patients had further anterior cruciate ligament injury. Twenty-four percent of patients (n = 22) sustained contralateral anterior cruciate ligament ruptures, and 8% (n = 7) ruptured the graft (P = .009). Graft rupture was associated with a graft inclination angle <17° (P = .02). Contralateral anterior cruciate ligament rupture was associated with age <18 years at time of primary injury (P = .001). All patients had normal or nearly normal (International Knee Documentation Committee evaluation) Lachman and instrumented testing, and 91% had a negative pivot-shift result. Seventy percent of patients had kneeling pain. Median subjective International Knee Documentation Committee evaluation was 91 of 100. Fifty-one percent of patients had radiographic evidence of osteoarthritis (41% grade B; 10% grade C).

CONCLUSION

Good results are maintained at 15 years after surgery with respect to ligamentous stability, subjective outcomes, and range of motion. Kneeling pain remains a significant problem. Concern remains regarding the incidence of further anterior cruciate ligament injury and the increasing number of patients with radiographic and clinical signs of osteoarthritis despite surgical stabilization.

Clinical cartilage imaging of the knee and hip joints

OBJECTIVE

MRI is commonly used to evaluate the articular cartilage of the knee and hip joints in clinical practice. This article will discuss the advantages and limitations of currently available MRI techniques for evaluating articular cartilage.

CONCLUSION

Because of its high spatial resolution, multiplanar capability, and excellent tissue contrast, MRI is the imaging technique of choice for evaluating the articular cartilage of the knee and hip joints.

Comparison between bovine bone and titanium interference screws for implant fixation in ACL reconstruction: a biomechanical study

INTRODUCTION

The application of interference screws for the fixation of bone-patellar tendon-bone (BPTB) grafts is a well-established technique in anterior-cruciate ligament reconstruction. Interference screws derived from bovine compact bone are a biological alternative to metallic or biodegradable polymer interference screws.

MATERIALS AND METHODS

In 60 porcine specimens, the tibial part of an anterior-cruciate ligament reconstruction was performed using a BPTB graft. To secure the graft, either an 8-mm titanium interference screw or a self-made bovine interference screw (BC), or a commercial bovine compact bone screw (Tutofix) was used. The maximum failure load was determined by means of a universal testing machine with computer interface at a testing speed of 50 mm/min. In a second test series, cyclic sub-maximal load was applied to the test specimen from 40 to 400 N with a number of 1,000 load cycles and a frequency of 1 Hz. Subsequently, the maximum failure load was determined. The stiffness of the test specimen was investigated in both test series. Each type of interference screw was tested 10 times.

RESULTS

A secure fixation of the grafts was achieved with all interference screws. In the experiments on the maximum load to failures, the titanium screws showed significantly higher failure loads than the Tutofix screws (P = 0.005). The stiffness of the grafts fixed with BC screws was significantly higher as compared to the fixation with Tutofix screws (P = 0.005). After cyclic sub-maximal loading, the maximum failure load of the titanium screws was significantly higher than that of the Tutofix screws (P = 0.033). The fixation of the BC screws showed a significantly higher failure load (P = 0.021) and stiffness (P = 0.032) than the Tutofix screw fixation. Except for two screw head fractures and two intra-tendinous graft ruptures, the failure mode was slippage in the interface between interference screw and bone plug.

CONCLUSION

Interference screws derived from bovine compact bone show similar good results as the titanium interference screws. Therefore, the safety and in vivo performance of products derived from xenogenic bone should be the focus of further investigations.

The impact of an Acute Knee Clinic

INTRODUCTION

The aim of this audit was to analyse the impact of an open access clinic for the treatment of soft tissue knee injuries with regard to delay to treatment.

PATIENTS AND METHODS

Data from 100 consecutive patients seen in our sports clinic in 2000 were collected. Following this audit, an Acute Knee Clinic was introduced and took place once per week. In 2006, the audit loop was closed and data from 100 consecutive patients seen in the Acute Knee Clinic were collected.

RESULTS

The time from injury to the first review by a specialist is referred to as the time to diagnosis. The introduction of the Acute Knee Clinic led to an 89% reduction in the time to diagnosis for accident and emergency referrals and a 32% reduction for general practitioner referrals. The average number of visits of any sort made by the patient prior to review by a specialist in 2000 was five as opposed to one in 2006.

CONCLUSIONS

An Acute Knee Clinic with open access is a simple method of dramatically reducing the delay to diagnosis. This decreases the total delay to treatment which is of particular importance in patients requiring anterior cruciate ligament (ACL) reconstruction due to the risk of secondary meniscal and chondral injuries. Decreasing the delay to diagnosis and appropriate treatment reduces the recovery time. This not only reduces the socio-economic cost of soft tissue knee injuries but may also decrease the psychosocial consequences for the patient. By reducing the number of times a patient is seen by medical practitioners prior to review by a specialist has the potential to decrease the total cost of treatment. The socio-economic impact and potential actual cost savings of treatment are particularly important with the current economic climate.

Torsional stability of interference screws derived from bovine bone--a biomechanical study

Background

In the present biomechanical study, the torsional stability of different interference screws, made of bovine bone, was tested. Interference screws derived from bovine bone are a possible biological alternative to conventional metallic or bioabsorbable polymer interference screws.

Methods

In the first part of the study we compared the torsional stability of self-made 8 mm Interference screws (BC) and a commercial 8 mm interference screw (Tutofix^®). Furthermore, we compared the torsional strength of BC screws with different diameters. For screwing in, a hexagon head and an octagon head were tested. Maximum breaking torques in polymethyl methacrylate resin were recorded by means of an electronic torque screw driver. In the second part of the study the tibial part of a bone-patellar tendon-bone graft was fixed in porcine test specimens using an 8 mm BC screw and the maximum insertion torques were recorded. Each interference screw type was tested 5 times.

Results

There was no statistically significant difference between the different 8 mm interference screws (p = 0.121). Pairwise comparisons did not reveal statistically significant differences, either. It was demonstrated for the BC screws, that a larger screw diameter significantly leads to higher torsional stability (p = 9.779 × 10^-5). Pairwise comparisons showed a significantly lower torsional stability for the 7 mm BC screw than for the 8 mm BC screw (p = 0.0079) and the 9 mm BC screw (p = 0.0079). Statistically significant differences between the 8 mm and the 9 mm BC screw could not be found (p = 0.15). During screwing into the tibial graft channel of the porcine specimens, insertion torques between 0.5 Nm and 3.2 Nm were recorded. In one case the hexagon head of a BC screw broke off during the last turn.

Conclusions

The BC screws show comparable torsional stability to Tutofix^® interference screws. As expected the torsional strength of the screws increases significantly with the diameter. The safety and in vivo performance of products derived from xenogeneic bone should be the focus of further investigations.

Autologous chondrocyte implantation versus microfracture for knee cartilage injury: a prospective randomized trial, with 2-year follow-up

The objective was to evaluate the functional performance over a 2-year period following autologous chondrocyte implantation (ACI) in an open knee procedure compared to microfracture. Objective functional outcome was studied as secondary analysis in a subgroup of patients, in a randomized clinical trial, with concealed allocation and independent evaluators. Sixty-seven patients with local cartilage defect, with a mean size of 2.4 cm(2) (SD 1.5) of the femoral condyle of the knee were included. Thirty-three patients underwent the microfracture and 34 the ACI procedure. An identical rehabilitation protocol was implemented for both groups. Active knee flexion and extension range, anterior laxity, knee extension strength (concentric at 60 degrees/s) and single leg hop performance (single hop, crossover triple hop and 6 m timed hop test) were evaluated pre-surgery and at 6, 9,12 and 24 months post-surgery. We calculated the symmetry index for individual and four performance tests pooled. Mixed linear model analyses were used with confidence interval set at 95%. The change over 2 years for the pooled performance-based tests was comparable between the two treatment arms. At 2 years, 70% (38/54) of all patients returned to >85% symmetry in overall functional performance. A decrease in functional performance at 6 months following ACI resulted in slower recovery at 9 and 12 months compared to microfracture. Rehabilitation following both cartilage repair procedures is a lengthy process. At 2 years after surgery, ACI patients have similar overall functional outcome compared to microfracture patients.

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

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

Prediction of patient-reported outcome after single-bundle anterior cruciate ligament reconstruction

PURPOSE

The purpose of this study was to identify preoperative and intraoperative factors that predict patient-oriented outcome as measured by the International Knee Documentation Committee (IKDC) Subjective Knee Form after anterior cruciate ligament (ACL) reconstruction.

METHODS

We identified 402 subjects who had undergone primary single-bundle arthroscopic ACL reconstruction at a mean follow-up of 6.3 years (range, 2 to 15 years). The IKDC Subjective Knee Form was used to measure patient-reported outcome and was dichotomized as above or below the patient-specific age- and gender-matched population mean. Potential predictor variables included subject demographics, activity level before surgery, previous meniscectomy, and surgical variables. Multivariate logistic regression analysis was performed to identify the best subset of predictors for determining the likelihood that the IKDC score was better than the age- and gender-matched population mean.

RESULTS

The dichotomized IKDC score was associated with body mass index (BMI), smoking status, education, previous medial meniscectomy, and medial chondrosis at the time of ACL reconstruction. The multivariate model containing only factors known before surgery included BMI and smoking status. Subjects with a BMI greater than 30 kg/m(2) had 0.35 times the odds of success as subjects with a normal BMI. Subjects who smoked had 0.36 times the odds of success as subjects who did not smoke. A model including medial chondrosis at the time of surgery had a slightly higher discriminatory power (area under the receiver operating characteristic curve, 0.65 v 0.61) and negative predictive value (71.4% v 60.0%) but similar positive predictive power (86.3% v 85.9%).

CONCLUSIONS

Lower patient-reported outcome after ACL reconstruction was strongly associated with obesity, smoking, and severe chondrosis at the time of surgery.

LEVEL OF EVIDENCE

Level III, prognostic case-control study.

Minimum 10-year results after anterior cruciate ligament reconstruction: how the loss of normal knee motion compounds other factors related to the development of osteoarthritis after surgery

BACKGROUND

Few long-term studies exist that evaluate how the loss of normal knee range of motion affects results after anterior cruciate ligament reconstruction.

HYPOTHESIS

Patients with normal knee motion will have higher subjective scores than patients with less than normal motion.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Patients were prospectively evaluated at >10 years after anterior cruciate ligament reconstruction according to International Knee Documentation Committee criteria. Normal knee motion was within 2 degrees of extension (including hyperextension) and 5 degrees of flexion compared with the uninvolved knee. Regression analysis was performed to determine what factors affected subjective scores.

RESULTS

Objective follow-up was obtained on 502 patients at a mean of 14.1 years postoperatively. Regression analysis showed that the most statistically significant factor related to lower subjective scores was lack of normal knee extension; loss of normal flexion was also significant. Patients who had meniscectomy or articular cartilage damage had statistically significantly lower subjective scores if they also had less than normal motion. Ninety-eight percent of patients with intact menisci, normal articular cartilage, and normal knee motion had normal radiographs; 29% of patients with normal motion had less than normal radiographs versus 71% of patients who had less than normal motion. The overall International Knee Documentation Committee objective grade was normal in 48%, nearly normal in 42%, abnormal in 9%, and severely abnormal in 0.5%.

CONCLUSION

The loss of 3 degrees to 5 degrees of knee extension, to include loss of hyperextension, adversely affected the subjective and objective results after surgery, especially when coupled with meniscectomy and articular cartilage damage.

Mood and attitude predict pain outcomes following arthroscopic knee surgery

BACKGROUND

Decreased pain represents a clinically important outcome following arthroscopic knee surgery. However, little is known about preoperative mood and attitudinal factors and their potential relationship with pain outcomes.

PURPOSE

This prospective, longitudinal study investigated the influence of preoperative depression, stress, and optimism on pain severity and interference with functioning, controlling for relevant demographic and clinical factors 1 year postoperatively.

METHODS

Participants (N = 180, mean age = 48.2 years) completed scales assessing pain severity and interference both preoperatively and postoperatively. Demographics, depression, stress, optimism, and body mass index were assessed preoperatively. Physicians assessed extent of knee osteoarthritis during surgery.

RESULTS

Hierarchical regression analyses controlling for relevant demographic and clinical variables revealed that optimism and stress were significant predictors of pain severity at 1 year but not pain interference. Extent of osteoarthritis predicted pain interference.

CONCLUSIONS

These findings support that optimism and stress are important predictors of patient-rated pain severity. They do not, however, predict the extent to which pain interferes with daily functioning.

A correlation of time with meniscal tears in anterior cruciate ligament deficiency: stratifying the risk of surgical delay

Two hundred and five patients with ACL rupture, who had been diagnosed pre-operatively by either MRI scan or knee arthroscopy, had reconstructions between 2003 and 2007. The diagnostic meniscal findings were compared with those at reconstruction, and any further damage along with time from diagnosis to reconstruction was recorded. Those patients with no meniscal damage at the time of diagnosis, and who had no further damage at surgery had a median time of 6 months. This time was significantly different from those with no meniscal damage at diagnosis, but who were found subsequently to have sustained damage to one meniscus, when the median time was 11 months (P = 0.0017) or both menisci, when the median time was 32 months (P = 0.0184). For patients with solitary ACL rupture undergoing a trial of conservative management, an early and thorough assessment of functional stability is essential. If the instability is unacceptable, the patient should be informed of the time dependent risk to the menisci with further delay to surgical reconstruction.

The association of pain and fear of movement/reinjury with function during anterior cruciate ligament reconstruction rehabilitation

STUDY DESIGN

Cross-sectional.

OBJECTIVES

To measure fear of movement/reinjury levels and determine the association with function at different timeframes during anterior cruciate ligament (ACL) reconstruction rehabilitation. We hypothesized that fear of movement/reinjury would decrease during rehabilitation and be inversely related with function.

BACKGROUND

Fear of movement/reinjury can prevent return to sports after ACL reconstruction, but it has not been studied during rehabilitation.

METHODS AND MEASURES

Demographic data and responses on the shortened version of Tampa Scale for Kinesiophobia (TSK-11), 8-Item Short-Form Health Survey (SF-8), and International Knee Documentation Committee (IKDC) subjective form were extracted from a clinical database for 97 patients in the first year after ACL reconstruction. Three groups were formed: group 1, less than or equal to 90 days; group 2, 91 to 180 days; group 3: 181 to 372 days post-ACL reconstruction. Group differences in TSK-11 score, SF-8 bodily pain rating, and IKDC scores were determined. Hierarchical linear regression models were created for each group, with IKDC score as the dependent variable and demographic factors, SF-8 bodily pain rating, and TSK-11 score as independent variables.

RESULTS

TSK-11 score was higher in group 1 than in group 3 (P < .05). Across the groups, SF-8 bodily pain rating decreased (P < .001) and IKDC score increased (P < .001). SF-8 bodily pain rating was a significant factor in the regression model for all groups, whereas TSK-11 score only contributed to the regression model in group 3 (partial correlation, -0.529).

CONCLUSIONS

Pain was consistently associated with function across the timeframes studied. Fear of movement/reinjury levels appear to decrease during ACL reconstruction rehabilitation and are associated with function in the timeframe when patients return to sports.

LEVEL OF EVIDENCE

Prognosis, level 4.

Tibial fixation of bone-patellar tendon-bone grafts in anterior cruciate ligament reconstruction: a cadaveric study of bovine bone screw and biodegradable interference screw

BACKGROUND

The use of interference screw fixation for bone-patellar tendon-bone grafts in anterior cruciate ligament fixation is well established. No previous study has compared bovine bone screws and biodegradable interference screws or demonstrated their efficacy for requirements associated with early rehabilitation.

HYPOTHESIS

There is no difference in tension loss and pull-out strength between bovine bone screws and biodegradable interference screws.

STUDY DESIGN

Controlled laboratory study.

METHODS

Anterior cruciate ligament reconstructions with bone-patellar tendon-bone allografts were performed in 40 human tibiae from 20 donors. A bovine bone screw and a polylevolactide interference screw were used for tibial fixation in each pair. A cyclic testing protocol with varying magnitude and orientation of the graft loading was developed. Cyclic tests were performed at 1 Hz for 5000 cycles with a peak force of 200 N applied to the graft. Survival rate and postcyclic-test pull-out strength were compared.

RESULTS

Fifteen of 20 reconstructions fixed with bovine bone screws and 17 of 20 fixed with biodegradable screws reached 5000 cycles. Graft tension drop after the 5000 cycles averaged 19.7 N ( +/- 12.9) for bovine bone screws and 18.9 N ( +/- 16.3) for biodegradable screws. There were no significant differences in tension loss and pull-out strength between the 2 types of screws.

CONCLUSION

Bovine bone screws are comparable to biodegradable interference screws in providing stable tibial fixation in anterior cruciate ligament reconstruction using bone-patellar tendon-bone allografts.

CLINICAL RELEVANCE

The use of bovine bone screws may be comparable to the popular biodegradable interference screws used for anterior cruciate ligament reconstruction in postsurgery rehabilitation.

Predictive factors for 12-month outcome after anterior cruciate ligament reconstruction

There is a lack of knowledge regarding predictive factors for a successful clinical outcome after an anterior cruciate ligament (ACL) reconstruction. The aim was to investigate pre-operative factors that may predict good outcomes as measured with the subscales Function in sports and recreation and Quality of life in Knee injury Osteoarthrithis Outcome Score (QOL-KOOS), one-leg hop test and Tegner Activity Scale 12 months after ACL reconstruction. Sixty-four patients, operated with either patellar or hamstring tendon graft, were included. Demographics, range of motion, anterior knee laxity, pivot shift, muscle-torques, anterior knee pain (AKP) and knee function were registered pre-operatively and used in a multiple regression model. Results show less degree of AKP and low influence on knee function to be the most important predictors for good outcome in Sport/Rec-KOOS (explained 31% of variances). Less AKP was in addition the most important predictor for QOL-KOOS (14%). Patellar-tendon graft, in favor of hamstring tendon graft, explained 8% of the improvement in the Tegner Activity Scale. In conclusion, a low degree of AKP was found to be the most important predictor for good clinical outcome 12 months after ACL reconstruction. Future studies, including psychological parameters, should use analyses that have the potential to control for independency between variables.

Primary anatomic double-bundle anterior cruciate ligament reconstruction: a preliminary 2-year prospective study

BACKGROUND

The anterior cruciate ligament consists of 2 functional bundles, the anteromedial bundle and the posterolateral bundle. Single-bundle anterior cruciate ligament reconstruction is the current standard for the treatment of anterior cruciate ligament deficiency. However, a significant subset of patients continues to report residual symptoms of instability after such reconstruction.

HYPOTHESIS

Anatomic double-bundle anterior cruciate ligament reconstruction may more closely restore normal kinematics of the knee by reproducing the native anatomy.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We report the current clinical outcomes of the initial 100 consecutive patients who underwent anatomic double-bundle anterior cruciate ligament reconstruction with an average follow-up of 2.1 +/- 0.5 years. All patients were prospectively followed to document range of motion, ligamentous laxity, and functional strength, as well as activity and sports participation.

RESULTS

Side-to-side difference in range of motion was 2 degrees +/- 3 degrees for extension and 2 degrees +/- 5 degrees for flexion. Sixty-five percent of patients had a normal Lachman test result, and 33% were nearly normal. For the pivot-shift test findings, 94% were normal, and 6% were nearly normal. The average side-to-side difference in the KT-2000 arthrometer test was 1.0 +/- 2.3 mm. There were 8 graft failures, 7 of which had subsequent revision surgery. No patients reported pain, swelling, or instability during activities of daily living, and 73% to 78% had no symptoms during very strenuous or strenuous sports activities. The scores of the International Knee Documentation Committee Subjective Knee Form, Activities of Daily Living, and Sports Activity Scores of the Knee Outcome Survey were 85.0, 91.8, and 87.0, respectively, and were similar compared with patients undergoing single-bundle anterior cruciate ligament reconstruction, which we have previously reported. Fifty-one percent described their current activity level as normal, and 35% reported it as nearly normal.

CONCLUSION

Anatomic double-bundle anterior cruciate ligament reconstruction results in good restoration of joint stability and patient-reported outcomes when evaluated 2 years after surgery.

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

BACKGROUND

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

HYPOTHESIS

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

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

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

RESULTS

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

Return to Sports After Anterior Cruciate Ligament Reconstruction – A Review of Patients with Minimum 5-year Follow-up

Introduction: It is difficult to counsel the anterior cruciate ligament (ACL) deficient patient considering surgical reconstruction on the likelihood of eventual return to sports as information on this is lacking, especially in the Asian context. We wanted to determine how many of our patients who had ACL surgery returned to their previous levels of sports, 5 years after their surgery. For those that had not returned to their previous levels of sports, we wanted to identify their reasons for not doing so. Materials and Methods: Based on our inclusion criteria of a minimum 5-year follow-up after primary ACL reconstruction, 146 patients were identified for assessment. Sixty-four patients were successfully recalled. The mean age of our patients was 24.8 years (range, 18 to 40). The patients completed the Lysholm Knee, Tegner activity and the Subjective International Knee Documentation Committee (IKDC) questionnaires. Clinical examination of the operated knee was performed according to the Objective IKDC evaluation form and with a KT-1000 arthrometer. Results: The mean Lysholm score was 85.2 and the mean subjective IKDC score was 79.5. 81.2% of our patients had normal or nearly normal knees (IKDC A or B) with the remaining 18.8% at IKDC grade C. The mean side-side difference for anterior translation using the KT-1000 arthrometer was 1.2 mm. The median pre-injury Tegner activity level was 7 and the median 5-year post-surgery Tegner activity level was 6. Nineteen patients did not return to their pre-injury sports levels because of social reasons and were excluded. From the remaining 45 patients, 28 patients (62.2%) returned to their previous level of sports and 17 patients (28.8%) did not return to their previous level of sports. Of whom, 9 (20%) said that they did not return due to fear of re-injury and the remaining 8 (17.8%) said they had not returned because of knee instability and pain. At 5 years, the subgroup of patients who had returned to sport had the best scores: Lysholm (88.5), subjective IKDC (84.6) and IKDC Grade A&B (89.3%). When we compared this with the subgroups that did not return to sport because of fear of re-injury and because of an unstable knee, we found that the difference in knee outcome scores between these 3 groups were statistically significant. Conclusion: Sixty-two per cent of our patients returned to their previous level of sport at 5 years after ACL reconstruction. Fear of re-injury is an important psychological factor for these patients not returning to sports. Our results would allow the attending surgeon to counsel the ACL deficient patient who is considering surgical reconstruction the likelihood of eventual return to sports. Key words: Ligament reconstruction, Return to sports

A histological and ultrastructural evaluation of the patellar tendon 10 years after reharvesting its central third

PURPOSE

This study was undertaken to evaluate the histologic and ultrastructural characteristics of the patellar tendon 10 years after reharvesting its central third.

HYPOTHESIS

In the long term, after its central third is reharvested, the patellar tendon does not regain a normal histological and ultrastructural appearance.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Twelve consecutive patients (4 women, 8 men) who underwent anterior cruciate ligament revision surgery using reharvested ipsilateral patellar tendon autografts were included in the study. Percutaneous biopsy samples were obtained from the central and lateral parts of the patellar tendon under ultrasonographic guidance at a median of 116 months (range, 102-127 months) after the revision procedure. Eleven biopsy specimens from asymptomatic patellar tendons obtained from open anterior cruciate ligament reconstructions served as controls. The histologic characteristics and the presence of glycosaminoglycans were assessed using a light microscope, and the ultrastructure was assessed using a transmission electron microscope.

RESULTS

The histological evaluation revealed deterioration in fiber structure, increased cellularity, and increased vascularity in both the central and peripheral parts of the reharvested patellar tendon specimens compared with normal tendon specimens. No difference in the amount of glycosaminoglycans was seen in specimens from either part of the reharvested patellar tendons and the control specimens. The ultrastructural evaluation revealed that all the control specimens had a normal morphologic appearance and a compact extracellular matrix with regularly oriented collagen fibrils. Furthermore, in the control specimens, the fibril diameter was heterogeneous, with all fibril size classes present. Specimens from the central and the lateral part of the reharvested tendon displayed pathological cell appearance and a more heterogeneous extracellular matrix. The lateral specimens from the reharvested tendons also displayed all fibril size classes but with a more homogeneous distribution. In the central specimens, the largest fibril size class was absent.

CONCLUSION

Ten years after its central third was reharvested for anterior cruciate ligament revision surgery, the patellar tendon had not normalized in terms of its histological and ultrastructural appearance.

Self-efficacy of knee function as a pre-operative predictor of outcome 1 year after anterior cruciate ligament reconstruction

The knee self-efficacy scale (K-SES) has been shown to have good reliability, validity and responsiveness during rehabilitation for patients' perceived self-efficacy of knee function. Determinants of self-efficacy of knee function 1 year after ACL reconstruction have been found to be the patients' internal locus of control and knee symptoms in sports and recreation. The predictive ability of perceived self-efficacy of knee function measured by the K-SES has not been studied in terms of patient outcome after an ACL reconstruction. The purpose of this study was to explore the potential for pre-operative self-efficacy of knee function measured by the K-SES to predict patient outcome in terms of physical activity, knee symptoms and muscle function 1 year after an ACL reconstruction. Thirty-eight patients were evaluated for outcome in terms of physical activity with the Tegner activity scale and the physical activity scale (PAS), knee symptoms with the Lysholm knee scoring scale and the knee injury and osteoarthritis outcome score (KOOS) and knee function with ability tests for muscle function 1 year after ACL reconstruction. Multiple regression and logistic multiple regression analysis were used to evaluate the K-SES as a possible predictor of outcome. The patients' present perceived self-efficacy of knee function (K-SES(Present)) pre-operatively was a significant predictor (P = 0.016) of the patients returning to their intensity and frequency of physical activity (PAS) 1 year after ACL reconstruction, when adjusted for age, gender and pre-injury physical activity level (Tegner(Pre-injury)) (odds ratio = 2.1). The patients' perceived future self-efficacy of knee function (K-SES(Future)) pre-operatively was a significant predictor (P = 0.045) of their self-rated knee function in sports/recreational activities (KOOS(Sports/recreation)) at the 1-year follow-up, when adjusted for age, gender and Tegner(Pre-injury )(R (2 )=0.25). The pre-operative K-SES(Future) was also a significant predictor (P = 0.023) of the patients' knee-related quality of life (KOOS(Qol)), at the 1-year follow-up, when adjusted for age, gender and Tegner(Pre-injury) (R (2 )=0.23). The pre-operative K-SES(Future) was furthermore a significant predictor of an acceptable outcome 1 year after surgery, on the Lysholm knee scoring scale (P = 0.003, odds ratio = 1.7), as well as on KOOS(Sports/recreation) (P = 0.002, odds ratio = 1.6) and knee-related quality of life (KOOS(Qol)) (P = 0.037, odds ratio = 1.4), when adjusted for age, gender and Tegner(Pre-injury). The pre-operative K-SES(Future) was also a significant predictor (P = 0.04) of an acceptable outcome 1 year after surgery, on the one-leg hop for distance (odds ratio = 2.2), when adjusted for age, gender and Tegner(Pre-injury). In conclusion, this study indicates that patients' perceived self-efficacy of knee function pre-operatively is of predictive value for their return to acceptable levels of physical activity, symptoms and muscle function 1 year after ACL reconstruction.

Osseous landmarks of the femoral attachment of the anterior cruciate ligament: an anatomic study

PURPOSE

Anatomic tunnel placement is critical to the success of anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to determine qualitatively and quantitatively the osseous landmarks of femoral attachment of the ACL.

METHODS

The femoral attachment of the ACL was studied histologically in seven human fetuses, arthroscopically in 60 patients who underwent ACL surgery, and grossly in 16 cadaveric knees. Three-dimensional laser digitizer pictures of the cadaveric specimens were taken to quantify length, area, and angulations of the femoral attachment of the ACL.

RESULTS

Two different osseous landmarks were detected. An osseous ridge that runs from proximal to distal ends was present in all the arthroscopic patients and cadaveric knees. It was named "lateral intercondylar ridge." Another osseous landmark between the femoral attachment of the anteromedial (AM) and posterolateral (PL) bundles running from anterior to posterior was observed in 6 out of 7 fetuses, 49 out of 60 arthroscopic patients, and 13 out of 16 cadaveric knees. It was named "lateral bifurcate ridge." A change of slope between the femoral attachment of the AM and PL bundles was observed in all specimens studied. The femoral attachment of the AM bundle formed an angle with the PL bundle of 27.6 degrees +/- 8.8 degrees and a radius of curvature of 25.7 +/- 12 mm. The area of the entire ACL footprint, AM, and PL bundle was 196.8 +/- 23.1 mm(2), 120 +/- 19 mm(2), and 76.8 +/- 15 mm(2), respectively.

CONCLUSIONS

The ACL femoral attachment has a unique topography with a constant presence of the lateral intercondylar ridge and often an osseous ridge between AM and PL femoral attachment, the lateral bifurcate ridge.

CLINICAL RELEVANCE

These findings may assist surgeons to perform ACL surgery in a more anatomic fashion.

Effect of ACL deficiency on MCL strains and joint kinematics

The knee joint is partially stabilized by the interaction of multiple ligament structures. This study tested the interdependent functions of the anterior cruciate ligament (ACL) and the medial collateral ligament (MCL) by evaluating the effects of ACL deficiency on local MCL strain while simultaneously measuring joint kinematics under specific loading scenarios. A structural testing machine applied anterior translation and valgus rotation (limits 100 N and 10 N m, respectively) to the tibia of ten human cadaveric knees with the ACL intact or severed. A three-dimensional motion analysis system measured joint kinematics and MCL tissue strain in 18 regions of the superficial MCL. ACL deficiency significantly increased MCL strains by 1.8% (p<0.05) during anterior translation, bringing ligament fibers to strain levels characteristic of microtrauma. In contrast, ACL transection had no effect on MCL strains during valgus rotation (increase of only 0.1%). Therefore, isolated valgus rotation in the ACL-deficient knee was nondetrimental to the MCL. The ACL was also found to promote internal tibial rotation during anterior translation, which in turn decreased strains near the femoral insertion of the MCL. These data advance the basic structure-function understanding of the MCL, and may benefit the treatment of ACL injuries by improving the knowledge of ACL function and clarifying motions that are potentially harmful to secondary stabilizers.

Ultrastructural collagen fibril alterations in the patellar tendon 6 years after harvesting its central third

BACKGROUND

Clinically, donor site problems are common, even in the long term after anterior cruciate ligament reconstruction using patellar tendon autograft. However, there is a lack of knowledge in terms of the mid- and long-term ultrastructural appearance of the previously harvested tendon in humans.

HYPOTHESIS

The patellar tendon does not regain normal ultrastructure 6 years after harvesting its central third and leaving the defect open.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Thirteen patients were included in the study. Biopsy specimens were obtained from the central and lateral thirds of the patellar tendon under ultrasound guidance 71 months (range, 68-73 months) after the reconstruction. Ten biopsy specimens from other subjects with asymptomatic patellar tendons served as controls. The sections were evaluated using transmission electron microscopy. Longitudinal sections were used for morphological evaluation, and the fibril diameter was measured on the transverse sections and grouped into 5 diameter classes.

RESULTS

All control specimens were found to have a compact extracellular matrix with regularly oriented collagen fibrils. Specimens from the lateral part of the harvested tendons displayed a more heterogeneous extracellular matrix. In 3 specimens, the extracellular matrix was different from that of the control specimens. Specimens from the central part of the harvested tendons displayed an even more heterogeneous extracellular matrix, with 8 specimens judged as heterogeneous. The fibril diameter in control specimens displayed the most heterogeneous pattern, and all 5 fibril classes were present. All fibril classes were found in the lateral biopsy specimens from the previously harvested tendons, but the 2 smallest fibril classes (0-30 and 31-60 nm) were significantly more dominant compared with control specimens (P < .0001). In the central specimens from the previously harvested tendons, only the 3 smallest size classes were found (P < .0001 vs controls).

CONCLUSION

Six years after harvesting its central third and leaving the defect open, the patellar tendon revealed a "more heterogeneous matrix" with changes in ultrastructural morphology and relative fibril diameter distribution compared with normal control tendon.

Anatomic double-bundle anterior cruciate ligament reconstruction

Anterior cruciate ligament (ACL) reconstruction is one of the most common procedures performed by orthopaedic surgeons. The procedure has improved significantly since its inception in 1900 and continues to be intensively studied with outcomes receiving considerable attention. Traditional ACL reconstruction techniques have focused on one portion of the ACL--the anteromedial bundle. Single-bundle ACL reconstruction is the criterion standard and has provided good to excellent results, with many athletes being able to return to sports; however, recently, some authors have noted persistent instability with functional testing and degenerative radiographic changes after single-bundle ACL reconstruction. As a result, several centers have attempted to improve upon the single-bundle technique by reconstructing both the anteromedial and posterolateral bundles of the ACL. This article will present the embryologic, anatomic, and biomechanical rationale for double-bundle ACL reconstruction. In addition, the latest outcomes of double-bundle ACL reconstruction will be presented.