***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: PURPOSE The purpose of this study was to analyze differences in the clinical results between a remnant-preserving augmentation and a double-bundle reconstruction . METHODS Between March 2008 and February 2009 , we prospect ively analyzed 100 cases of anterior cruciate ligament reconstruction with a minimum follow-up period of 2 years . There were 55 cases of remnant-preserving augmentation and 45 cases of double-bundle reconstruction . We clinical ly compared the preoperative and postoperative range of motion , visual analog scale score , Lysholm score , Tegner score , International Knee Documentation Committee knee evaluation form score , anterior drawer test , Lachman test , pivot-shift test , KT-1000 arthrometer ( MEDmetric , San Diego , CA ) test , and anterior translation on  Telos stress radiographs ( Telos , Weiterstadt , Germany ) . RESULTS There were no significant differences in the postoperative range of motion , visual analog scale score , Lysholm score , Tegner score , and International Knee Documentation Committee knee evaluation form score between the 2 groups ( P > .05 ) . The anterior drawer test was significantly better in the remnant-preserving augmentation group than the double-bundle reconstruction group ( P = .038 ) . However , there were no significant differences in the Lachman test , pivot-shift test , anterior translation on Telos stress radiographs , and KT-1000 arthrometer test between the 2 groups ( P > .05 ) . CONCLUSIONS Clinical outcomes of a remnant-preserving augmentation and a double-bundle reconstruction showed similar results in terms of anterior and rotary stability and clinical scores . LEVEL OF EVIDENCE Level IV , therapeutic case series There is a dearth of reliable and valid instrumentation that measures disability following injury and /or surgery of the knee joint that is responsive to clinical ly significant changes over time . The purpose of this investigation was to determine whether  performance-based or patient-reported measures of function  are more effective in estimating disability in individuals with an anterior-cruciate-ligament (ACL)-deficient knee .  Subjective rating of knee function was used as the criterion measure for disability , and selected performance-based and patient-reported measures were used as estimation variables . Twenty-nine individuals with an ACL-deficient knee participated in this investigation . Step-wise regression analysis revealed that the Cincinnati Knee Scale , Lysholm Knee Scale , and hop index were the most effective estimates of disability . The results demonstrate that patient-reported measures are more related to the patient 's level of disability in individuals with an ACL-deficient knee . More research is necessary to substantiate these findings Background : There is controversy regarding the efficacy of remnant tissue preservation on graft healing in anterior cruciate ligament ( ACL ) reconstruction . Hypothesis : The preserved remnant tissue will ( 1 ) adhere to the graft surface and undergo a remodeling process , ( 2 ) accelerate graft revascularization , ( 3 ) increase the number of graft mechanoreceptors by 4 weeks , and ( 4 ) improve anteroposterior knee laxity and structural properties of the graft by 12 weeks . Study Design : Controlled laboratory study . Methods : Forty-two sheep were r and omly divided into 2 groups of 21 animals . In group I , the ACL was completely removed . In group II , the ACL was transected at the midsubstance but not debrided . ACL reconstruction was performed using a semitendinosus tendon autograft in both groups . Histological changes of the grafted tendon and the remnant tissue were evaluated at 4 and 12 weeks after surgery . Biomechanically , anterior translation and knee joint stiffness under an anterior drawer force and the structural properties of the femur-graft-tibia complex were evaluated . Results : The preserved remnant tissue was histologically distinct from the graft at 4 weeks , while the tissue partially adhered to the graft surface at 12 weeks . The ACL remnant tissue significantly accelerated revascularization in the grafted tendon at 4 weeks and significantly increased the number of mechanoreceptors at 4 and 12 weeks . In addition , remnant preservation significantly improved anterior translation ( 9.3 ± 2.1 mm and 5.4 ± 1.7 mm at 60 ° of knee flexion in groups I and II , respectively ) and knee joint stiffness at 12 weeks . However , there were no significant differences in the structural properties between the 2 groups at 4 and 12 weeks after surgery . Conclusion : Preservation of the ACL remnant tissue in ACL reconstruction enhanced cell proliferation , revascularization , and regeneration of proprioceptive organs in the reconstructed ACL and reduced anterior translation . However , remnant preservation did not improve the structural properties of the graft . Clinical Relevance : These results imply that preservation of the ACL remnant tissue may improve graft healing after ACL reconstruction PURPOSE Our purpose was ( 1 ) to compare the structural integrity and healing capacity of the acutely repaired anterior cruciate ligament ( ACL ) remnants and ( 2 ) to determine whether the short-term postoperative biomechanical results of the acute remnant-repairing anterior cruciate ligament reconstruction ( ACLR ) were superior to the conventional ACLR . METHODS An acute complete ACL femoral detachment model was created in 50 rabbits . The rabbits were immediately r and omly allocated into the remnant-repairing ACLR group ( group 1 , n = 25 ) and the conventional ACLR group ( group 2 , n = 25 ) . Each animal in both groups was subjected to unilateral ACLR with semitendinosus tendon autografts . During ACLR , the ACL remnants were acutely repaired with the femoral-tensioning technique in group 1 , whereas the ACL remnants were debrided in group 2 . The outcomes of the remnant were macroscopically evaluated in group 1 . The remnant 's structural integrity and remnant-to-graft healing capacity were divided into 3 categories ( grade A , good ; grade B , fair ; or grade C , poor ) according to 2 distinct criteria . Biomechanical tests including the anterior tibial translation test at 30 ° and 90 ° of knee flexion and tensile tests were compared between groups . All the macroscopic evaluations and biomechanical tests were performed postoperatively at week 12 . RESULTS The macroscopic evaluations of the ACL remnants in group 1 ( n = 25 ) showed that the remnants ' structural integrity was grade A ( well-maintained continuity with an adequate amount of tissue and tension on probing ) in 10 specimens ( 40 % ) , grade B ( fairly maintained continuity with thin and slack fibers detected ) in 5 ( 20 % ) , and grade C ( resorption with no remnant left in situ ) in 10 ( 40 % ) . The remnant-to-graft healing capacities among the specimens with surviving remnants ( grade s A and B for structural integrity , n = 15 ) were all classified as grade C ( an obvious remnant-to-graft interval through the entire length of the graft ) . For the biomechanical tests , there were no significant differences between the groups ( 25 in each group ) with respect to the anterior tibial translation test at 30 ° ( P = .15 ) and 90 ° ( P = .91 ) of knee flexion and stiffness ( P = .66 ) , ultimate failure load ( P = .11 ) , and elongation at failure ( P = .92 ) . CONCLUSIONS In our rabbit model of ACL femoral detachment , the acutely repaired ACL remnants showed a high resorption rate , low healing capacity , and poor biomechanical properties . The acute remnant-repairing ACLR had no evident superiority over the conventional ACLR  in rabbits . CLINICAL RELEVANCE The findings did not support the contention that the remnant-repairing ACLR , even performed in the acute setting , could produce better postoperative knee joint stability outcomes than the conventional ACLR BACKGROUND  Anterior cruciate ligament ( ACL ) reconstruction with remnant preservation technique had been thought to be a more favorable milieu for graft reinnervation , revascularization , and ligamentization . However , the influence of preserving tibial residual fibers on mRNA expression during the graft remodeling process has never been investigated . MATERIAL S AND METHODS Healthy mature New Zeal and white rabbits were r and omly assigned to one of four groups : remnant dissected , remnant preserved , sham operated , and normal control . Ligament tissue was dissected at 2 , 6 , and 12 wk after surgery , and real-time PCR was performed using primers for VEGF , TGF-β1 , COLlAl , COL3A1 , GAP-43 , and NT-3 . RESULTS In the remnant preservation group , mRNA levels for matrix components COL l Al , COL3A1 , growth factor TGF-β1 , and nerve-related genesGAP-43 all increased 6 wk after surgery , compared with the remnant dissection group ( P < 0.05 ) . An increased level of VEGF mRNA was also detected in the remnant preservation group 12 wk after operation ( P < 0.05 ) . An increased level of NT-3 mRNA was also observed in the remnant preservation group 2 and 12 wk after operation ( P < 0.05 ) . CONCLUSIONS Our results suggest that there is a time dependent alteration of angiogenesis-promoting , repair-related , and nerve-related gene expression after ACL reconstruction during the process of graft remodeling . Furthermore , they demonstrate that remnant preservation in ACL reconstruction determines the different molecular profiles of these target genes , especially during the early stages of graft remodeling , which perhaps explains the potential role in promoting revascularization , reinnervation , and ligamentization We prospect ively studied knee proprioception  following ACL reconstruction in 40 patients ( 34 men and six women ; mean age 31 years ) . The patients were allocated into two equal groups ; group A underwent reconstruction using hamstrings autograft , and group B underwent reconstruction using bone-patellar tendon-bone autograft . Proprioception was assessed in flexion and extension by the  joint position sense ( JPS )  at 15 ° , 45 ° and 75 ° , and  time threshold to detection of passive motion ( TTDPM ) at 15 ° and 45 ° , preoperatively and at 3 , 6 and 12 months postoperatively . The contralateral healthy knee was used as internal control . No statistical difference was found between the ACL-operated and the contralateral knees in JPS 15 ° , 45 ° and 75 ° at 6 and 12 months , in both study groups . No statistical difference was found between the ACL-operated and the contralateral knees in TTDPM 15 ° at 6 and 12 months , nor regarding TTDPM 45 ° at 3 , 6 and 12 months , in group A. No statistical difference was found in JPS and TTDPM between the two grafts , at any time period . Knee proprioception returned to normal with ACL reconstruction at 6 months postoperatively , without any statistically significant difference between the autografts used STUDY DESIGN Nonr and omized prospect i ve study . OBJECTIVE To evaluate proprioception in 2 groups of patients with anterior cruciate ligament ( ACL ) deficiency who had different severity of symptoms . BACKGROUND Defective proprioception has previously been found in patients with ACL-deficient knees . It has been suggested that sensory receptors of the ACL and other knee joint ligaments contribute to proprioception and knee joint function and stability . METHODS AND MEASURES A total of 17 patients with ACL deficiency ( mean [ SD ] age , 28.8 + /- 5.6 years ; range , 22 - 39 years ) with few , if any , symptoms were compared with 20 patients with ACL deficiency ( mean [ SD ] age , 26.6 + /- 6.1 years ; range , 18 - 39 years ) having instability and episodes of giving way . The groups were compared with each other and with an age-matched reference group of 19 nonimpaired subjects . Their mean ( SD ) age was 25.6 + /- 3.7 years ( range , 20 - 37 years ) . Three tests of proprioception were used : threshold to detection of passive motion from 2 starting positions ( 20 degrees and 40 degrees of knee flexion ) toward flexion and extension , active reproduction of a 30 degrees passive angle change , and visual reproduction of a 30 degrees passive angle change . The Wilcoxon rank sum test was used for between-group comparisons . RESULTS Symptomatic patients had higher threshold to detection of passive motion in their injured side in the flexion trial from 20 degrees ( median of 1.5 degrees vs median of 0.5 degree ) and in the extension trial from 40 degrees ( median of 1.0 degree vs median of 0.5 degree ) than the asymptomatic patients . No differences were found in the other threshold tests , active or visual reproduction tests . CONCLUSIONS Patients with severe symptoms related to ACL deficiency were found to have inferior proprioceptive ability in some measurements compared with patients with a good knee function . The findings indicate that proprioceptive deficits might influence the outcome of an ACL injury treated nonoperatively Objective The aim of this work was to compare the prevalence of cyclops lesions  after anterior cruciate ligament reconstruction ( ACLR )  using the single-bundle and remnant bundle preservation techniques . Material s and methods One hundred consecutive patients , who had undergone postoperative MRI of the knee followed by arthroscopic ACLR with the remnant bundle preservation technique ( R ) between February 2007 and August  
    Output:
    
Recent studies have shown proprioceptive deficits , in both the injured and contralateral knees , with the clinical relevance of findings limited by testing methodology and the small differences found .