Introduction: Cell-based strategies for regeneration and reconstitution of musculoskeletal tissues are gaining interest. The difficulty in obtaining the required amount of mesenchymal stem cells (MSC) stems from their scarcity and the time needed to grow them in culture. We developed a rapid and efficient method to isolate MSC from bone marrow aspirate based on their surface markers, as a platform for future cell based therapy.

Methods: Bone marrow was aspirated from the iliac crest of fifteen adult subjects undergoing surgeries involving this bone. 15 ml samples were obtained, fractionated for mononuclear cells and then subjected to immunomagnetic isolation using microbeads of directly conjugated mouse anti–human CD105 antibodies. Recovered cell fraction was analyzed for phenotype and functional parameters.

Results: The samples yielded an average of 14.6±2.5x10⁶ mononuclear cells per ml. Of these, fraction of CD105 positive cells consisted of 2.3±0.45%, which accounts for 0.25±0.06x10⁶ cells per ml. Post isolation analysis shows that 79±3.2% were positively stained for CD105 and 36±5.8% stained positive for CD45. These cells generated 6.3±1.4 Colony Forming Units (CFU) per 10⁵ cells. MSC concentration is higher in males and lower in smokers. Processing time is approximately 3 hours.

Discussion and Conclusion: Regeneration of mesenchymal tissues using progenitor cells with appropriate matrix and signals was shown feasible, however large numbers of these rare cells are needed. An effective and safe method for purification of autologous MSC enables us to avoid the risks and the time span associated with culture expansion. We conclude that this method is both effective and rapid.

Introduction Musculoskeletal injuries, especially fractures, cause reduced limb mobilization. The diminished limb activity promotes muscular atrophy, leading to a slower return to function. Attempts to prevent this atrophy using electrical stimulation have been described after knee reconstruction.

The Myospare percutaneous electrical stimulator has been developed to prevent immobilization related atrophy. We undertook this pilot study to assess feasibility, safety, and efficacy of applying electrical stimulation under a cast after ankle fractures.

Patients and Methods Between May and December 2004, patients who sustained closed ankle fractures requiring surgery, were recruited to participate in this study. 24 patients took part in the study, sixteen male and eight female. Age range was 18 to 62 years (average 40). All patients underwent open reduction and internal fixation using standard AO technique. A short walking cast was applied after surgery. Patients were randomized into a treatment and a control group. The experimental device was applied in the treatment group for 6 weeks. Patients were examined at 2, 6 and 12 weeks.

Evaluation included measurement of calf and ankle circumference, dorsiflexion and plantiflexion, and calculation of the ratio between the injured and uninjured side. At each visit pain intensity was assessed using a visual analog score, and patients filled out a function assessment questionnaire. Analysis was performed using chi square, t-test and repeated measures analysis.

Results All patients tolerated the stimulator well. No adverse effects were encountered. There is a trend toward improvement in calf diameter, dorsiflexion and plantarflexion. However, with the small number of patients in this study, no significant difference was apparent. Functional recovery and VAS scores were borderline higher in the treatment group at 12 weeks (p=0.043 and p=.049) when compared to baseline.

Discussion The use of the Myospare device under a cast in patients after surgical fixation of ankle fractures has been demonstrated as feasible and safe. In this pilot study a trend toward enhanced recovery was apparent in the treatment group.