Cellular repopulation of deep-frozen meniscal autografts: An experimental study in the dog

This study evaluated the cellular repopulation of deep-frozen meniscal autografts. Medial menisci of adult dogs were excised, deep-frozen in liquid nitrogen (-196 degrees C) for 10 min, and orthotopically reimplanted into the joint. Deep-freezing was found to effectively kill all the cells within the meniscus as determined by the absence of Na(2)35SO4 incorporation. Following orthotopic replacement within the knee joint, menisci were repopulated with cells that seemed to originate from the adjacent synovium. These cells migrated over the surface of the meniscus and began to invade the deeper layers of the tissue. However, even after 6 months, the central core of the meniscus remained acellular. While the new cells appeared to modulate into cells that are similar in appearance to meniscal fibrochondrocytes, the exact phenotypic expression of these newly differentiated cells has yet to be determined. Histological alterations, as manifested by a loss of normal orientation of the collagen architecture of the superficial layers of the meniscus; was evident at 6 months and suggests that a remodeling phenomenon may be associated with the cellular repopulation. While biomaterial studies have not been carried out on these specimens, the morphologic alterations observed in the collagen orientation would suggest a possible alteration in the material properties of the repopulated meniscus. The clinical implication of this study is that the structural remodeling associated with the cellular repopulation of deep-frozen meniscal allografts may make the transplanted meniscus more susceptible to injury.     

Recovery of natural fertility after grafting of cryopreserved germinative tissue in ewes subjected to radiotherapy

OBJECTIVE: To recover natural fertility of ewes that were subjected to ovarian failure induced by radiotherapy with an autologous orthotopic graft of cryopreserved germinative tissue. DESIGN: Experimental surgery study. SETTING: University hospital unit. ANIMAL(S): Adult ewes. INTERVENTION(S): Four ewes were submitted to right oophorectomy and posterior dissecting and freezing of the germinative tissue. Afterward, they were administered radiotherapy to induce infertility on the remaining left ovary. Later, two of the ewes had the thawed fragments of the right ovary injected inside the cortex of the irradiated left ovary in a "sowing" procedure that eliminated the need for sutures. MAIN OUTCOME MEASURE(S): Recovery of fertility in ewes after transplantation of germinative tissue into the ovary destroyed by radiotherapy. RESULT(S): The ewes were housed with fertile rams. Six months following the grafting, the rams impregnated the transplanted ewes. More than 2 years after radiotherapy, the nongrafted (control) ewes have not become pregnant. CONCLUSION(S): Intracortical grafting of the germinative tissue circumvents the obstacle of vascular anastomosis with autologous ovarian implants. Patients could benefit from the subcortical grafting of germinative tissue in one of the ovaries, recovering fertility after radiotherapy treatment for malignancy.     

Cranioplasty with bone flaps preserved under the scalp

Cranial bone defects in 27 patients were repaired with bone flaps preserved under the scalp. Head trauma (thirteen patients), cerebrovascular disorder (five patients), postoperative brain swelling (seven patients), and cerebral infective disease (two patients) accounted for the cranial defects. The bone flaps are reimplanted after 14–98 days. The follow-up period was 6 to 26 months. We have encountered no complications releated to this technique in 27 consecutive cases.     

骨膜成骨细胞培养活体自体、异体和异种移植成骨的实验研究

目的 研究培养骨膜细胞在不同条件下移植成骨情况.方法 取人胎儿胫骨膜和兔胫骨膜分离成骨细胞培养、传代和增殖,然后注射移植到异种、异体和自体活体内,经肉眼和组织学切片检查.结果 培养骨膜成骨细胞自体移植生成骨和软骨,异体和异种移植无骨或软骨生成,在移植局部引起免疫反应.结论 骨膜成骨细胞经培养、传代和增殖后仍具有成骨细胞的特性.自体移植能够生成骨和软骨.     

自体角膜缘干细胞移植术治疗复发性翼状胬肉

目的：观察自体角膜缘干细胞移植术治疗复发性翼状胬肉的临床效果。方法：对33例36眼复发性翼状胬肉采取显微镜下手术切除局部病灶联合自体角膜缘干细胞移植术。术后随访6～36个月。平均20个月。结果：术后植片存活良好。无排斥反应或其它并发症发生。随访期间1眼复发。复发率为2．78％。结论：自体角膜缘干细胞移植术为受损的角膜缘提供新的健康的干细胞,有效地防止翼状胬肉的复发,是一种治疗复发性翼状胬肉的简单、安全、有效的手术方法。     

Small Size Autograft versus Large Size Allograft in Anterior Cruciate Ligament Reconstruction

BackgroundA small autograft diameter negatively affects functional outcomes, knee stability, and the risk of rerupture after anterior cruciate ligament (ACL) reconstruction, whereas the strength of allograft decreases over time. Therefore, it is not clear whether the use of smaller autografts or the use of larger allografts in ACL yields better results. The aim of this study was to compare the outcome of smaller autografts and larger allografts for ACL reconstruction.MethodsFifty-one patients who underwent ACL reconstruction with hamstring tendon autografts (size ≤ 8 mm) and 21 patients who underwent ACL reconstruction with allografts (size ≥ 10 mm) were included in our study. All patients underwent the same aggressive early postoperative rehabilitation program. There were no significant differences between the autograft and allograft groups regarding the preoperative patient age, sex, time from injury to surgery, and average follow-up time.ResultsThe mean diameter of the 4-stranded hamstring tendon grafts used as autografts was 7.48 ± 0.33 mm and the mean diameter of the allografts was 10.76 ± 0.67 mm. According to specific tests for the ACL (anterior drawer, Lachman, and pivot shift) and clinical evaluation tests (Lysholm knee scoring scale and International Knee Documentation Committee questionnaire), the final follow-up results were significantly better than the preoperative status in both autograft and allograft ACL reconstruction groups. Therefore, there were no significant differences between the autograft and allograft groups preoperatively and at the final follow-up.ConclusionsThe large size of the graft in ACL reconstruction has been reported to affect results positively. However, in our study, we could not find any significant differences between the smaller size autografts and larger size allografts in terms of inadequacy, rerupture, and final follow-up functional results. Although allografts were significantly larger than autografts, we did not have the positive effect of larger size grafts. Smaller size autografts were as effective as the larger size allografts.     

兔眼前房子宫内膜自体移植模型的研究

兔眼前房子宫内膜自体移植模型的研究袁科，吴燕婉，宗书东２．活体观察术后１周以后，将兔用豚酯麻醉（同前），固定在一个特制的观察台上，用丝线将眼睑拉开固定，用一台装有照像和录像装置的Ｚｅｉｓｓ手术型显微镜，观察，摄片和录像。光源为无热源的纤维光源灯，以免...     

Comparison of Clinical Outcome of Autograft and Allograft Reconstruction for Anterior Cruciate Ligament Tears

Background:

Hamstring (HS) autograft and bone-patellar tendon-bone allograft are the most common choice for reconstruction of anterior cruciate ligament (ACL). There was a little report about the clinical outcome and difference of arthroscopic ACL reconstruction using allograft and autograft. This study aimed to compare the clinical outcome of autograft and allograft reconstruction for ACL tears.

Methods:

A total of 106 patients who underwent surgery because of ACL tear were included in this study. The patients were randomly divided into two groups, including 53 patients in each group. The patients in group I underwent standard ACL reconstruction with HS tendon autografts, while others in group II underwent reconstruction with bone-patellar tendon-bone allograft. All the patients were followed up and analyzed; the mean follow-up was 81 months (range: 28–86 months). Clinical outcomes were evaluated using the International Knee Documentation Committee (IKDC), Lysholm scores, physical instability tests, and patient satisfaction questionnaires. The complication rates of both groups were compared. Tibial and femoral tunnel widening were assessed using lateral and anteroposterior radiographs.

Results:

At the end of follow-up, no significant differences were found between the groups in terms of IKDC, Lysholm scores, physical instability tests, patient satisfaction questionnaires, and incidences of arthrofibrosis. Tibial and femoral tunnel widening was less in the HS tendon autografts. This difference was more significant on the tibial side.

Conclusions:

In the repair of ACL tears, allograft reconstruction is as effective as the autograft reconstruction, but the allograft can lead to more tunnel widening evidently in the tibial tunnel, particularly.     

Factors influencing arthrodesis rates in a rabbit posterolateral spine model with iliac crest autograft

Purpose

The rabbit posterolateral intertransverse spine arthrodesis model has been widely used to evaluate spinal biologics. However, to date, the validity and reproducibility of performance of iliac crest bone graft, the most common and critical control group, has not been firmly established. We evaluated original research publications that utilized this model, identified which experimental conditions affected fusion rates, and developed an algorithm to predict fusion rates for future study designs.

Methods

A MEDLINE search was performed for publications through December, 2011 that utilized this model to evaluate fusion rates elicited by iliac crest autograft. All study parameters were recorded, and logistic regression analyses were performed to determine the effects of these variables on fusion rates as determined by either manual palpation or radiographs.

Results

Seventy studies with 959 rabbits in 102 groups met the inclusion criteria. Excluding studies that measured fusion at 4 or fewer weeks or intentionally tried to decrease the fusion rate, the overall fusion rate for autograft was 58.3 ± 16.3 % (mean ± SD) as determined by manual palpation and 66.4 ± 17.8 % by plain radiographs. Regression analysis demonstrated a difference between these outcome measures with a trend towards significance (p = 0.09). Longer time points and larger volumes of autograft resulted in significantly greater reported fusion rates (p < 0.0001 and p < 0.05, respectively). Neither strain, age, weight, nor vertebral level significantly affected fusion rates.

Conclusions

Although experimental conditions varied across studies, time point evaluation and autograft volume significantly affected fusion rates. Despite some variability demonstrated across certain studies, we demonstrated that when the time point and volume of autograft were controlled for, the iliac crest control group of the rabbit posterolateral spinal arthrodesis model is both reliable and predictably affected by different experimental conditions.     

Bone graft from greater trochanter in posterior wall fractures with impacted fragments

Background

Posterior wall fracture is the most common acetabular fracture. Comminuted fractures with an impacted segment represent a subtype of this injury. The subchondral bone of the articular zone is compressed and causes a bone defect. The impacted fragment should be isolated, mobilized, and then reduced. A bone graft should be used to fill the gap. The other fragments are fixed following the reduction of the impacted segment.

Materials and methods

Ten patients with comminuted fractures and impacted segments with bone defects were enrolled in our study, from January 2010 to July 2012. Autogenous bone grafts from the greater trochanter were used to fill the gap in all patients. The reduction was achieved through the insertion of the graft above the impacted fracture, and plate fixation was performed subsequently. Merle d’Aubigne and Postel scoring, modified by Matta, was applied to evaluate the patients during follow-up. The mean follow-up was 12 months.

Results

The clinical results included one “excellent”, four “very good”, four “good” and one “poor”. Pain in the zone of graft harvesting was not detected in any patient. Femoral head necrosis was observed in one case. No other severe complications were detected.

Conclusions

Using an autogenous bone graft to fill the bone defect supplies excellent mechanical stability without any severe complications at the donor site. This surgical technique seems to be effective and safe in treating a comminuted fracture of the posterior wall in association with an impacted segment.

Level of evidence

Level IV.