Intraarticular Injection of Allogenic Mesenchymal Stem Cells has a Protective Role for the Osteoarthritis.

BACKGROUND: Researchers initially proposed the substitution of apoptotic chondrocytes in the superficial cartilage by injecting mesenchymal stem cells (MSCs) intraarticularly. This effect was termed as bio-resurfacing. Little evidence supporting the treatment of osteoarthritis (OA) by the delivery of a MSC suspension exists. The aim of this study was to investigate the effects of injecting allogenic MSCs intraarticularly in a rat OA model and to evaluate the influence of immobility on the effects of this treatment. METHODS: We established a rat knee OA model after 4 and 6 weeks and cultured primary bone marrow MSCs. A MSC suspension was injected into the articular space once per week for 3 weeks. A subgroup of knee joints was immobilized for 3 days after each injection, while the remaining joints were nonimmobilized. We used toluidine blue staining, Mankin scores, and TdT-mediated dUTP-biotin nick end labeling staining to evaluate the therapeutic effect of the injections. Comparisons between the therapy side and the control side of the knee joint were made using paired t-test, and comparisons between the immobilized and nonimmobilized subgroups were made using the unpaired t-test. A P value < 0.05 was considered significant. RESULTS: The three investigative approaches revealed less degeneration on the therapy sides of the knee joints than the control sides in both the 4- and 6-week groups (P < 0.05), regardless of immobilization. No significant differences were observed between the immobilized and nonimmobilized subgroups (P > 0.05). CONCLUSIONS: Therapy involving the intraarticular injection of allogenic MSCs promoted cartilage repair in a rat arthritis model, and 3-day immobility after injection had little effect on this therapy.

[Imaging reasons for periprosthetic femoral fractures during the operation of total hip arthroplasty with anatomic prosthesis].

OBJECTIVE: To explore the imaging reasons for periprosthetic femoral fractures during the operation of total hip arthroplasty with anatomic prosthesis. METHODS: The fracture group consisted of 7 cases with periprosthetic femoral fracture (PPFF) and the non-fracture group 21 cases without PPFF during the operation of total hip arthroplasty (THA) among the 144 cases of primary THA with anatomic prosthesis. The preoperative plain films of hip joint were taken to calibrate the Sharp's angle, centre edge (CE) angle, femoral neck shaft angle, femoral anteversion angle of neck, bowing angle of proximal femoral shaft part, width of narrowest part in proximal femoral shaft. For each case, surgical details, age, height and weight were recorded. The results were analyzed with independent sample t test by software SPSS 17.0. RESULTS: No significant difference existed in general situation, Sharp's angle and CE's angle between two groups. And there were significant differences in femoral neck shaft angle (P = 0.040), femoral anteversion angle of neck (P = 0.026), bowing angle of proximal femoral shaft part (P = 0.024), width of narrowest part in proximal femoral shaft (P = 0.021). CONCLUSION: Dysplasia of proximal femur is a major cause of periprosthetic femoral fracture during the operation of total hip arthroplasty with anatomic prosthesis.

[The etiologies and prevention of patellar instability after un-resurfaced total knee arthroplasty].

OBJECTIVE: To investigate the etiologies and prevention of patellar instability after total knee arthroplasty (TKA). METHODS: From September 1997 to April 2005, 94 patients (105 knees) underwent TKA without patellar resurfacing. All of them were osteoarthritis. Ten patients (14 knees) were performed with Rotation Knee (RK) prostheses. Forty patients were performed with mobile bearing TACK prostheses, and 44 patients with GEMINI prostheses. Subluxation and tilt of patella were evaluated by X-rays before or after operation. RESULTS: The incidence of patellar instability after operation was 28.6% in patients who had genu valgus deformity, and was 29.5% in whom had patellar instability preoperative. The incidence of patellar instability in RK, TACK, and GEMINI group was 28.6%, 20.9%, and 16.7% respectively after operations. Four patients had obvious femoral or tibial components malrotation. CONCLUSIONS: The etiologies of patellofemoral instability include pre-operative conditions, prosthetic design, and improper positioning of the prosthetic component. So the suitable component design and skillful operative technique will help the surgeon to avoid this complication.

[Surgical treatment for degenerative lumbar scoliosis associated with spinal stenosis].

OBJECTIVE: To study surgical techniques for degenerative lumbar scoliosis associated with lumbar stenosis and evaluate their clinical significane. METHODS: Thirty-two patients with degenerative lumbar scoliosis associated with spinal stenosis were treated by techniques of posterior lumbar interbody fusion or posterolateral fusion and pedicle screws. There were 18 male and 14 female with 56.8 years old on the average (ranging from 49 to 75 years). There were no evident change of lumberlordosis in 15 cases, and lumber lordosis were obvious loss associated with lumbar subluxation in 17 cases. The correcting, the improvement of back and leg pain, complications and followed-up results were analyzed retrospectively. RESULTS: Thirty-two cases were followed-up for 6 to 39 months (the average time of 13 months). The average correction rate of scoliosis was 58.0% and the rate of pain relief was (80.2 +/- 5.8)%. There were two cases of dura sac laceration, two cases of nerve roots injury and a case of pseudoarthritis. During followed-up, correction rate and height of disc spaces were not lost. Shift of interbody cages were no displaced; all the internal fixation got well fusion and the rate of fusion for the bone graft was 96.9%. CONCLUSION: Posterior pedicle screws combined with interbody fusion or posterolateral fusion is a safe and effective surgical treatment for degenerative lumbar scoliosis associated with lumbar stenosis.

[Change in the joint line after total knee arthroplasty].

OBJECTIVE: To investigate the change in joint line after knee arthroplasty. METHODS: A total of 43 patients had 25 primary cruciate-retaining total knee replacements (Link Gemini MKII) and 25 rotational knee replacements (Link Endo-Model Rotational Knee System) sacrificing collateral ligaments and cruciate ligaments. Lateral radiographs were made both preoperatively and postoperatively. The change in the relative position of the joint line preoperatively and postoperatively was defined as the difference between the perpendicular distance from the weight-bearing surface of the tibial plateau to the tibial tubercle of the natural tibia (JL) and perpendicular distance from the weight-bearing surface of the prosthetic tibial component to the tibial tubercle (JL'). This distance was JL'-JL. The statistical differences between 2 groups were analyzed. RESULTS: The distance of JL'-JL was 2.0 mm (-1.3 - 7.2 mm) in 22 patients with Gemini replacement, whereas the distance was 3.1 mm (-1.5 - 12.3 mm) in the other patients with rotational knee system. The difference was significant. CONCLUSIONS: If the collateral ligaments and cruciate ligaments are removed during the knee replacement operations, the prosthetic joint line is likely to be malpositioned proximally. The fibular styloid and medial or lateral epicondylar reference points can be used to determine proper position of the joint line during operation.