Comparison of Bone-Patellar Tendon-Bone Graft, Semitendinosus-Gracilis Graft and Semitendinosus-Gracilis with Preserved Tibial Insertion Graft in Anterior Cruciate Ligament Reconstruction in Sports Persons.

INTRODUCTION: Bone-patellar tendon-bone (BPTB) and semitendinosus-gracilis (STG) are the commonest grafts used for ACL reconstruction. However even after having been debated for years, there is no consensus about the ideal graft. Moreover, the literature is deficient about STG graft with preserved tibial insertion (STGPI) which preserves the proprioception. Our aim is to compare the outcome of BPTB, free STG and STGPI grafts after ACL reconstruction in professional sports persons. We compared the outcome in terms of mechanical stability, functional outcome, return to sports activity and degenerative changes. MATERIAL AND METHODS: Professional sports persons aged between 16-50 years operated for ACL tear using BPTB, free STG and STGPI grafts with minimum follow-up of two years were identified from hospital records. Patients with associated knee injuries were excluded. Patients, divided in three groups according to graft used, were compared in terms of mechanical stability (arthrometric examination KT-1000 score), functional outcome (Lysholm Score), return to sports activity (Tegner score and difference in thigh circumference) and degenerative changes (KL grading). RESULTS: BPTB graft group was found to be better than free STG and STGPI graft groups in terms of KT-1000 score. There was no statistically significant difference among the groups in terms of Lysholm score, Tegner score, difference in thigh circumference and KL grading. CONCLUSION: BPTB graft is better than free STG and STGPI grafts in terms of knee stability. When compared for patient reported outcome, return to sports activity, osteoarthritic changes and graft failure there is no significant difference among the three types of grafts.

Predictors for Anterior Cruciate Ligament (ACL) Re-injury after Successful Primary ACL Reconstruction (ACLR).

INTRODUCTION: Few authors have addressed risk factors related to an ipsilateral graft rupture and contralateral anterior cruciate ligament (ACL) injury after return to sports (RTS) following primary ACL reconstruction. MATERIAL AND METHODS: Patients with ACL re-injury to either knee after successful primary ACLR were included in Group I and those with no further re-injury were included in Group II. Variables including age, gender, side, body mass index (BMI), thigh atrophy, anterior knee laxity difference between both knees measured by KT-1000 arthrometer, mean time of return to sports (RTS), graft type, type of game, mode of injury, Tegner Activity Score, hormone levels, femoral tunnel length (FTL), posterior tibial slope (PTS) and notch width index (NWI) were studied. Binary logistic regression was used to measure the relative association. RESULTS: A total of 128 athletes were included with 64 in each group. Mean age in Group I and II were 24.90 and 26.47 years respectively. Mean follow-up of Group I and Group II were 24.5 and 20.11 months respectively. Significant correlation was present between ACL re-injury and following risk factors; PTS of >10º, KT difference of >3.0mm, thigh atrophy of >2.50cm and time to RTS <9.50 months P value <0.05). No correlation was found with age, sex, BMI, type of game, Tegner Activity Score, mode of injury, NWI, size of graft, FTL and hormone levels. CONCLUSION: Possible risk factors include PTS of ≥ 10º, KT difference of ≥ 3.0mm at 1 year follow-up, thigh atrophy of ≥ 2.50cm at 1 year follow-up and RTS <9.5 months after primary ACLR.

Identification of natural ligands for SH2 domains from a phage display cDNA library.

The cytoplasmic domain of the Fc gamma receptor IIB (FcgammaRIIB) can be successfully displayed on the surface of filamentous phage, and after phosphorylation in vitro, can interact specifically with the SH2 domains of SHP-2, a cytoplasmic tyrosine phosphatase. When full-length FcgammaRIIB is expressed on phage, however, this interaction is greatly compromised, illustrating that characteristics of the full-length sequence are not well tolerated by the phage display system. Many associations in cell physiology are driven by similar interactions involving small modular binding domains or ligands, and so a fragmented cDNA library will facilitate display of such domains free of sequences which compromise their expression. A fragmented leukocyte cDNA display library of 10(8) clones was constructed. This library was phosphorylated in vitro with fyn kinase and was selected against the tandem SH2 domains of SHP-2 in the search for additional ligands. A depletion strategy to remove non-specific clones was employed, using SHP-2 Sepharose, prior to in vitro phosphorylation and selection. This permitted the emergence of clones encoding the cytoplasmic domain of PECAM-1, another natural ligand for SHP-2. The importance of dual phosphorylation of tyrosine residues at positions 663 and 686 was confirmed in competition ELISA experiments using phosphorylated phage and synthetic peptides. Thus, phage display of fragmented cDNA libraries permits the identification and characterisation of phosphorylated ligands of modular binding domains based on their functional interaction.

Synthesis of azaalanine peptides using the solid phase method.

The methodology for the incorporation of azaamino-acid residues into peptides synthesised by a solid-phase method has been extended to allow azaalanine peptides to be prepared. In this way, Ac-Leu-Ser-Gly-azaAla-Gly-Phe-Ser-Leu-NH2 H-Ala-Ala-Lys-Glu-Ala-Ala-Glu-Ala -Ala-Glu-Lys-Ala-azaAla-Glu-Leu-Ala-Leu-N2H3, and H-Ala-azaAla-Lys-Glu-Ala-Ala-Glu-Ala-Ala-Glu-Lys-Ala-Ala-Glu-Leu-A la-Leu-N2H3 have been prepared. A new analogue of the Ala-Gly sequence, 3-azaalanylpropionic acid has been prepared and used to prepare the peptide analogue acetyl-Leu-Ser-Gly-azaAla-3-Prop-Phe-Ser-Leu-NH2.