Takahide Miyama

Single- versus bi-socket anterior cruciate ligament reconstruction using autogenous multiple-stranded hamstring tendons with EndoButton femoral fixation *: A prospective study

PURPOSE This prospective study was conducted to compare the single-socket and the bi-socket anterior cruciate ligament (ACL) reconstruction techniques in terms of outcome. TYPE OF STUDY Nonrandomized control trial. METHODS There were 160 consecutive patients with unilateral chronic ACL insufficiency who underwent endoscopic single- or bi-socket ACL reconstruction alternately using multiple-stranded medial hamstring tendon and EndoButton (Smith & Nephew, Andover, MD) femoral fixation. All patients underwent the same postoperative rehabilitation protocol. Of them, 106 patients (57 single, 49 bi) were available for 2-year follow-up. RESULTS According to the IKDC Knee Ligament Evaluation Form, 23 patients (40%) of the single-socket group were subjectively graded as normal, 30 (53%) as nearly normal, and 4 (7%) as abnormal. Twenty-six patients (53%) of the bi-socket group were graded as normal, 21 (43%) as nearly normal, and 2 (4%) as abnormal (P =.19). The mean side-to-side anterior laxity difference (KT-1000 manual maximum force) was 0.9 +/- 1.8 mm for the single-socket group and 0.7 +/- 1.2 mm for the bi-socket group (P =.44). Fifty-three of 57 patients (93%) in the single-socket group and all patients in the bi-socket group showed anterior laxity differences of +/-3 mm or less (P =.12). There were no differences in thigh muscle strength between the groups. CONCLUSIONS Both single- and bi-socket ACL reconstruction using autogenous multiple-stranded hamstring tendons with EndoButton fixation provided satisfactory anterior stability, and there were no statistically significant differences in subjective results or measured restored stability between the 2 groups.

Human meniscus cell: characterization of the primary culture and use for tissue engineering.

Human meniscus cells from 47 surgically excised menisci were grown in primary culture. Cell proliferation and morphologic features were evaluated in three different culture media. Human meniscus cells showed three distinguishable cell types in monolayer culture: elongated fibroblastlike cells, polygonal cells, and small round chondrocytelike cells. These cells proliferated in Dulbecco’s modified Eagle’s medium, but by Day 7, elongated fibroblastlike cells became predominant. Cells did not proliferate in Ham’s nutrient mixture-F-12. In a mixture of Ham’s nutrient mixture-F-12 and Dulbecco’s modified Eagle’s medium, cells proliferated, maintaining their morphologic features and their ability to express messenger ribonucleic acids for aggrecan and Types I, II, and III collagen. Hyaluronan enhanced cellular proliferation without altering morphologic features or chondroitin sulfate production. Cultured human meniscus cells attached to a porous collagen sponge after cell seeding. Gene transfer was successful and an introduced gene was expressed by the cells, indicating that human meniscus cells can undergo gene manipulation. The finding that cells collected from small surgical specimens of human meniscus could be cultured, propagated, and seeded onto a collagen scaffold holds promise for the development of a cell-based, tissue engineered collagen meniscus.

Cell-Based Therapy in Articular Cartilage Lesions of the Knee

PURPOSE The purpose of this systematic review was to determine the effectiveness of cell-based therapy for articular cartilage defects of the knee. METHODS We performed a literature search in Medline (1994 to 2009) regarding cell-based therapies for chondral lesions. RESULTS We identified 10 Level I or II randomized controlled trials and 3 Level II prospective comparative studies. Although many of these studies had substantial flaws, which could introduce bias, we overall found no difference between the cell-based studies and other interventions. In addition, we identified 26 Level III and IV studies of cell-based therapy. CONCLUSIONS There is insufficient evidence from the studies included in this review to say whether cell-based therapy is superior to other treatment strategies in articular cartilage lesions of the knee.

Effect of irrigation solutions for arthroscopic surgery on intraarticular tissue: comparison in human meniscus-derived primary cell culture between lactate Ringer’s solution and saline solution

In order to determine whether there is a difference in effect on cell morphology and function between two common arthroscopic irrigation solutions, primary cultures of cells derived from the surgically excised human menisci were incubated for 3 or 6 h in lactated Ringers solution, isotonic sodium chloride solution, or serum‐free cell culture medium (negative‐control condition). Cell integrity was blindly evaluated by three independent examiners scoring photomicrographs of the cell cultures on a battery of five‐point scales for abnormality of cell shape, irregularity of cell membrane, change of cell size and cell density. Cell cultures were also quantitatively assayed by semi‐quantitative reverse‐transcription‐polymerase‐chain‐reaction for mRNA of α1 (I) procollagen, α1 (II) procollagen, aggrecan and heat‐shock protein 70 to assess functional consequences of exposure to the solutions. There was a statistically significant difference in cell integrity scores between either lactated Ringers solution or serum‐free cell‐culture medium and isotonic sodium chloride solution with greater damage to cells displayed. Scores for lactated Ringers solution did not differ from those for serum‐free cell‐culture medium. There were no significant differences in mRNA expression level among the treatment conditions. It was concluded that the lactated Ringers solution better maintained human meniscus cell integrity than the isotonic saline.

Arthroscopic reduction and internal fixation of an avulsion fracture of the posterior horn of the lateral meniscus.

We report a very rare case of an avulsion fracture of the posterior horn of the lateral meniscus associated with ACL tear, which was successfully treated by arthroscopic reduction and pullout fixation of the fragment along with ACL reconstruction.

Intra-articular corrective osteotomy for malunited Hoffa fracture: A case report

Hoffa fracture, an isolated coronal plane fracture of the posterior aspect of the femoral condyle, is known as an unstable, intra-articular fracture, and therefore, operative treatment is recommended. However, insufficient open reduction or failure of fixation may lead to malunion. We performed intra-articular corrective osteotomy for a malunited Hoffa fracture in a 31-year-old man and obtained good functional and radiographic results. This report suggests that intra-articular corrective osteotomy for malunited Hoffa fracture offers a good outcome and should be considered as salvage treatment.

PERIARTICULAR GENE EXPRESSION OF OSTEOPONTIN AND PROGRESSION IN OSTEOPENIA FOLLOWING JOINT IMMOBILIZATION

In order to elucidate the molecular events involved in periarticular osteopenia following joint immobilization, we investigated the temporal and spatial gene expression of one of the major non-collagenous bone matrix proteins, osteopontin (OPN), in periarticular regions, after immobilizing rat knee joints. Significant decreases in total BMD was observed in the immobilized limbs after 2 weeks of immobilization. Histologically, multinucleated cells with positive staining for tartrate resistant acid phosphatase (TRAP) were significantly increased in the metaphyseal regions, 1 to 4 weeks following immobilization. In situ hybridization studies revealed that OPN mRNA was present in a significantly larger number of cells in the metaphysial regions of joints immobilized for 1 to 3 weeks; compared with those levels detected in the control limbs, OPN mRNA was mainly detected in osteoblast/osteocyte-lineage cells of the spongiosa. Such temporal and spatial similarities in the expression of TRAP-positive multinucleated cells and OPN transcripts suggest the possible involvement of OPN in the periarticular osteoclastogenesis, leading to the activation of regional bone resorption following joint immobilization.