Effects of different bone marrow stimulation techniques on avascular zone meniscal defects.

OBJECTIVES: In this study, we sought to investigate the effect of different amounts of Bone Marrow-Derived Mesenchymal Stem Cells (BMSCs), obtained by different BMSCs, on the healing of avascular zone meniscal defects. BACKGROUND: Treating avascular zone meniscal injuries has gained popularity. BMSCs contribute to the healing of avascular zone meniscal defects. The amount of BMSCs derived from different bone marrow stimulation techniques (BMSTs) varies, which could affect the therapeutic efficacy of this treatment. METHODS: Fifty-four skeletally mature female New Zealand White rabbits were used after local ethical committee approval. A full thickness, 1.5 mm diameter defect was produced in the inner two-thirds of the anterior portion of the medial meniscus avascular zone using a biopsy punch. Animals were enrolled into three different groups according to BMST (0.8 mm, 1.5 mm, and 4 mm). Medial menisci were harvested and prepared for histomorphometric, histologic and immune-histologic analyses. RESULTS: Larger bridging tissues across the defect were detected in the 1.5-mm and 4-mm groups at 4 weeks (p < 0.05). The best quality score at the 1-,4- and 12-week endpoints was in 0.8 mm, 4 mm and 0.8 mm, 1.5 mm, respectively (p 0.05)CONCLUSION: The largest amount of BMSCs did not correlate with best quality and largest quantity of bridging tissue at the avascular zone in meniscal defects (Tab. 3, Fig. 4, Ref. 30).

Comparison of interfragmentary pinning versus the extension block technique for acute Doyle type 4c mallet finger.

The aim of this study was to compare the closed reduction interfragmentary pinning method (IPM) with the extension block technique (EBT) for bony mallet finger. Patients who underwent mallet finger operations were screened retrospectively for the following inclusion criteria: Doyle type 4c, age between 18 and 75 years, less than 4 weeks to surgery, and more than 1 year of follow-up time. Group I underwent a closed reduction IPM, and group II underwent the EBT. Lateral radiographs taken during the preoperative and final examination were used to evaluate the size and amount of displacement from the distal interphalangeal (DIP) joint and the dorsal fragment as well as the articular surface. Operation times were compiled from patient records. During the final examination, pain and DIP joint range of motion (ROM) were assessed and complications were recorded. The Crawford criteria were used for functional results. Fifteen patients in group I (8 men, 7 women) and 17 patients in group II (10 men, 7 women) were evaluated. Age, gender, time to surgery and follow-up time showed no statistically significant differences between the two groups. The differences in fragment size, preoperative and postoperative joint displacement, amount of dorsal displacement and DIP joint ROM were not statistically significant between the two groups. However, the operation time was significantly shorter time in group I than in group II (p=0.000). The average time to fracture union was significantly longer in group I (7.3 weeks) than in group II (6 weeks) (p=0.013). The EBT has faster time to union and is a safer method with lesser risk of arthritis and fragmentation. The IPM can be an alternative with shorter operation time, less pin bed infection and nail bed damage, especially in Doyle type 4c cases with large fragments.