Various studies have demonstrated that menisci heal in the vascular region but do not heal in the avascular area. Experimental studies of the promotion of meniscal healing in the avascular area have involved the application of fibrin clot, fibrin glue to the injured area, as well as the construction of an access chanel to the vascular regiòn, all of them with poor results. The multilineage potential of adult stem cells has been characterized extensively. The adipose tissue has been described as a useful source of adult stem cells. We try to show that the use of stem cells from the adipose tissue may promete meniscal healing in the avascular area.

Twelve New Zealand white rabbits with a mean weight of 3 kg were used. The medial meniscus of both knees was aproached, and was performed a longitudinal tear in the avascular area in the anterior horn with a mean length of 0.5 cm. All the tears were sutured with one vertical stitch of nonabsorbable suture. In each rabbit a solution with 1 00 000–1 000 000 stem cells from the fat was introduced in one of the knees, and the other one was used as a control. The rabbits were killed at 12 weeks, and a macro-microscopic study of the meniscus was done, and also a inmunohistochemistry study for the stem cells.

The incidence of healing was better in those menisci with the stem cells solution. Three total and three partial healing was obtained in the stem cells group and none in the control group. The inmunohistochemistry showed that the stem cells were in the repair zone.

We think that stem cells will be very useful in the treatment of the lesion in the avascular area of the meniscus.

Introduction and purpose: The Gamma nail (Howmedica, Kiel) was designed in the eighties as an alternative to sliding plate-screw systems for the treatment of per and subtrochanteric lesions of the proximal femur. The purpose of this study is to analyze eight instances where a breakage of the gamma nail occurred trying to establish possible causes and therapeutic alternatives.

Materials and methods: This is a retrospective study on 1478 Gamma nails implanted in our hospital between 1989 and 2002 (standard: 1287, long: 174; trohchanteric: 17). 11 cases of material breakage were detected, of which three corresponded to the breakage of the distal screws and eight to breakages of the nail itself. The clinical records and imaging tests of these patients were carefully scrutinized.

Results: The standard Gamma nail failure rate was .15% (2 breakages) and that of the long Gamma nail was 3.4% (2 breakages). The breakages occurred a mean of 15.6 months after the initial procedure. In 5 cases the nail broke at a site of fracture malunion and in the other three they broke in fully healed or nearly healed fractures.

Conclusions: Gamma nail breakage is an unusual complication. Our failure rate was similar to those published by other authors. In most cases nail breakage was related to malunited fracture. In these cases we withdrew the implant and implanted a new intramedullary device which led to healing.

Introduction and purpose: The relationship between congenital heart disease and the increased prevalence of scoliosis is well known, although the same cannot be said about the etiology of scoliosis in these patients. Although thoracotomy is often associated to scoliosis, median sternotomy has so far not been identified as an etiological agent. he purpose of the study is to determine if patients with congenital heart disease who are subjected to a median sternotomy show a higher prevalence of spine deformities.

Materials and methods: A retrospective review is made of patients operated on for congenital heart disease through median sternotomy before the age of 8, assessing the development of spine deformities. Simple chest radiographs of 128 patients were studied once they reached skeletal maturity and it was observed that they presented no spinal or costal deformities before surgery.

Results: The prevalence of scoliosis was 34.3%; 16 of these patients (12.5%) had curves of more than 20° and 33 (25.8%) had thoracic kyphosis of less than 20°. Patients operated on before the age of 18 months had a significantly higher risk to develop scoliosis as compared with those treated later (odds ratio: 3.48; p=0.016). The development of scoliosis was not related with the type of cardiac malformation present.

Conclusions: There is a high prevalence of scoliosis in patients subjected to a median sternotomy for a congenital heart pathology. The prevalence of scoliosis increases in patients operated on at younger ages.

Introduction and purpose: Pelvic tilt (PT) on the sagittal plane when standing can be defined as the rotation of the pelvis on a transverse axis. The use of PT is indicated for patients with chronic lumbar pain and/or spondylolisthesis. Current IP measurement methods require the use of radiographs or very complicated equipment. The purpose of this study is to describe a new fast and easy-to-use IP measurement technique and analyze its validity and reproducibility.

Materials and methods: The measurement system consists in calculating the height of the anterosuperior and posterosuperior iliac spines (to the ground) and the distance between them. Then, by means of a mathematical formula, a determination is made of the inclination of the plane that runs through the four spines with respect to the horizontal. Reproducibility was analyzed through repeat measurements of a group of 12 healthy volunteers. The validity of the method was analyzed by comparing the measurements obtained with those made on the basis of the lateral pelvis radiographs of 30 volunteers.

Results: The system described can be used to calculate the value of IP fast and with no need of radiographs or complicated equipment. The intraclass interobserver correlation coefficient measured for the method was .90 and the interobserver correlation coefficient was .80, which were considered excellent results. The mean errors observed when comparing the values obtained with the radiograph measurements were of less than 2° (R2: .48) (significant p< 0.001).

Conclusions: The measurement method described is easy to use, reproducible and valid vis-á-vis the use of radiographs.

Introduction and Objectives: Periprosthetic fractures are a complication seen with increasing frequency, owing in part to the growing number of patients undergoing total hip arthroplasty, older patient age, osteoporosis, revision surgeries, etc. Many classification systems have been described as a guide for optimal treatment in each situation. The aim of this study is to present our experience in recent years in the treatment of this pathology.

Materials and Methods: This is a retrospective study of clinical records and radiographic studies of patients diagnosed with periprosthetic fractures associated with both cemented and cementless total hip arthroplasty beginning in 1995. Intraoperative fractures were excluded from the study. We collected data on patient age, gender, type of total hiparthroplasty (THA), time to fracture, etiology, previous hip history, type of fracture, type of treatment, and complications.

Results: A total of 35 cases were reviewed, including 28 females (80%) and 7 males (20%). Average age was 73 years (33–93). Most common previous hip conditions were arthrosis, subcapital fracture, and revision THA. Of the fractures, 56% occurred with cementless THA and 44% with cemented. There was no history of trauma in 22% of the cases. Most common fractures were type B1 and B2. Conservative treatment was used in 10 cases with minimally-displaced fractures or in patients with a poor state of overall health. The remaining patients were treated with various surgical techniques. In 2 cases of postoperative fractures, intraoperative fractures or reaming defects were found which had previously been overlooked. Of fractures in patients who had undergone THA more than 10 years previously (5 cemented and 2 cementless), 5 patients required revision THA, and in 2 cases, surgical treatment was not elected due to high risk of medical complications. One patient required intervention for aseptic loosening of the femoral stem, and one patient underwent Girdlestone arthroplasty for an infected non-union.

Discussion and Conclusions: For optimal results, definitive treatment must be tailored to the individual and must be guided by the surgeon’s good judgement. Surgeons should balance the benefits and risks of aggressive and conservative treatments. Although there has been a low rate of non-union, we believe that cancellous or cortical allografts should be used more frequently to encourage bone healing.