Francesco Pegreffi

Predisposing Factors for Recurrent Shoulder Dislocation After Arthroscopic Treatment

BACKGROUND Arthroscopic repair of anterior dislocation of the shoulder can fail. We hypothesized that patients who are at higher risk for redislocation following repair could be recognized preoperatively on the basis of their clinical history. The purpose of the present study was to identify the risk factors for recurrence in a community-based population of patients with traumatic unidirectional instability that was treated with a single arthroscopic technique. METHODS From January 2000 to December 2003, 625 patients with anterior unidirectional instability were managed with an arthroscopic Bankart technique, and 385 met the criteria for inclusion in the study. Demographic data were collected, and clinical follow-up was performed at three, six, twelve, twenty-four, and thirty-six months. RESULTS At thirty-six months, thirty-one patients (8.1%) had experienced a redislocation; the rate was 13.3% among patients who were twenty-two years of age and younger and 6.3% among older patients. Age at the time of the first dislocation, male sex, and the time from the first dislocation until surgery were significant risk factors for recurrence (p < 0.05 for all). CONCLUSIONS Patients who are more likely to have a redislocation following arthroscopic repair of an anterior shoulder dislocation can be identified preoperatively on the basis of sex, age, and the time from the first dislocation to surgery.

Dynamic hip screw compared with external fixation for treatment of osteoporotic pertrochanteric fractures. A prospective, randomized study.

BACKGROUND Although the use of a sliding hip screw is considered to be the preferred treatment for pertrochanteric femoral fractures, we theorized that external fixation could produce clinical outcomes equal to, if not better than, the outcomes obtained with conventional treatment. Furthermore, because external fixation is minimally invasive, we expected a lower rate of morbidity and a reduced need for blood transfusions. Therefore, we compared the two treatments in a clinical trial of elderly patients with pertrochanteric fracture. METHODS Forty consecutive elderly female patients who had a pertrochanteric fracture were randomized to be treated with either fixation with a 135 degrees four-hole sliding hip screw (Group A) or an external fixation device with hydroxyapatite-coated pins (Group B). The inclusion criteria were female gender, an age of at least sixty-five years, an AO/OTA type-A1 or A2 fracture, and a bone mineral density T-score of less than -2.5. There were no differences in patient age, fracture type, bone mineral density, comorbidities, length of hospital stay, or quality of reduction between the two groups. RESULTS The average intraoperative time (and standard deviation) was 64 +/- 6 minutes in Group A and 34 +/- 5 minutes in Group B (p < 0.005). The average number of units of blood transfused postoperatively was 2.0 +/- 0.1 in Group A and none in Group B (p < 0.0001). Group B had less pain five days postoperatively (p < 0.05). Varus collapse of the fracture at six months averaged 6 degrees +/- 8 degrees in Group A and 2 degrees 1 degrees in Group B (p < 0.002). No pin-track infections occurred in Group B. The average Harris hip score at six months was 62 +/- 19 points in Group A and 63 +/- 17 points in Group B. CONCLUSIONS This study showed that external fixation with hydroxyapatite-coated pins is an effective treatment for this fracture in this patient population. The operative time is brief, the blood loss is minimal, the fixation is adequate, and the reduction is maintained over time.

HA-coated screws decrease the incidence of fixation failure in osteoporotic trochanteric fractures.

This study was done to determine if elderly patients with trochanteric fractures and with osteoporosis could benefit from treatment with a dynamic hip screw fixed with HA-coated AO/ASIF screws. One hundred twenty patients with AO, A1, or A2 trochanteric fractures were selected. Patients were divided into two groups and randomized to receive a 135°-four–hole dynamic hip screw fixed with either standard lag and cortical AO/ASIF screws (Group A), or HA-coated lag and cortical AO/ASIF screws (Group B). Lag screw cutout occurred in four patients in Group A, but not in any patients in Group B. In Group A, the femoral neck shaft angle was 134° ± 5° postoperatively and 127° ± 12° at 6 months. In Group B, the femoral neck shaft angle was 134° ± 7° postoperatively and 133° ± 7° at 6 months. The Harris hip score at 6 months was 60 ± 25 in Group A and 71 ± 18 in Group B. The superior results of Group B can be attributed to the increased screw fixation provided by the HA-coated screws. We recommend lag screws coated with HA for dynamic hip screw fixation, especially in osteoporotic bone.

Alendronate improves screw fixation in osteoporotic bone

BACKGROUND Animal studies have demonstrated the efficacy of the use of bisphosphonates to enhance screw fixation in bone. In this prospective, randomized study of pertrochanteric fractures treated with external fixation, we tested whether systemic administration of bisphosphonates would improve the fixation of hydroxyapatite-coated screws implanted in osteoporotic bone. METHODS Sixteen consecutive patients with a pertrochanteric fracture were selected. Inclusion criteria were female gender, an age of at least sixty-five years, and a bone mineral density T-score of less than -2.5 standard deviations. Exclusion criteria included bisphosphonate treatment during the two-year period prior to the fracture. Fractures were fixed with a pertrochanteric fixator and four hydroxyapatite-coated pins. Two pins were implanted in the femoral head (pin positions 1 and 2), and two were placed in the femoral diaphysis (pin positions 3 and 4). The patients were randomized either to therapy with alendronate for a three-month postoperative period (Group A) or to no therapy (Group B). The Group-A patients received an oral dose of 70 mg of alendronate per week. The fixators were removed after three months. RESULTS All of the fractures healed, and no loss of reduction, nonunion, or delayed union was observed. The combined mean extraction torque (and standard deviation) of the pins implanted at positions 1 and 2 (cancellous bone) was 2558 +/- 1103 N/mm in Group A and 1171 +/- 480 N/mm in Group B (p < 0.0005). The combined mean extraction torque of the pins implanted at positions 3 and 4 (cortical bone) was 4327 +/- 1720 N/mm in Group A and 4075 +/- 1022 N/mm in Group B. CONCLUSIONS These data show that weekly systemic administration of alendronate improves pin fixation in cancellous bone in elderly female patients with osteoporosis. We observed a twofold increase in extraction torque with the pins implanted in cancellous bone. These results support the use of alendronate in the treatment of osteoporotic pertrochanteric fractures to improve screw fixation in the femoral head.

Hydroxyapatite-coated external fixation pins

A sheep model was developed for the implantation of 84 bicylindrical stainless steel external fixation pins. One-half of the pins were coated with hydroxyapatite, and the rest remained uncoated. A set of 6 pins with the same coating was implanted in the lateral side of the left tibias of 14 sheep, the final insertion torque was measured, and a monolateral external fixator was assembled on the pins. The medial tibial middiaphysis then was exposed and a 5-mm resection osteotomy was done. Sheep were euthanized 6 weeks after surgery, radiographs were taken, and the initial extraction torque was measured on 4 pins from each sheep. Undecalcified sectioning and histologic and histomorphometric analyses were done on the remaining 2 pins. Radiographic pin tract rarefaction was significantly lower in the hydroxyapatite coated pins compared with the uncoated pins. Group average insertion torque was 960 ± 959 Nmm in the hydroxyapatite coated pins and 709 ± 585 Nmm in the uncoated pins. Group average initial extraction torque was 1485 ± 1308 Nmm and 298 ± 373 Nmm, respectively. Bone pin contact was 85.7% ± 8.9% and 50.3% ± 20.4%, respectively, in hydroxyapatite coated and uncoated pins. Bone between the threads was 95.6% ± 5.7% and 80% ± 8.7%, respectively, in hydroxyapatite coated and uncoated pins. Hydroxyapatite coating was effective for improving the bone-to-pin interface.

Cast vs external fixation: a comparative study in elderly osteoporotic distal radial fracture patients.

Aim: This study compared fracture treatment with plaster cast vs external fixation. Methods: Forty elderly female osteoporotic wrist fracture patients were randomized to be treated with either plaster cast (Group A) or external fixation (Group B). Bone mineral density less than −2.5 T-score was among the inclusion criteria. Results: In Group A, four redisplacements occurred, whereas in Group B there were none (p = 0.005). Horesh score was higher in Group B (p < 0.006) than in Group A. Volar angle deformity (p < 0.0005) and radial angle deformity (p = 0.008) were lower in Group B. Conclusions: This study shows that external fixation improves stability in elderly osteoporotic wrist fracture patients.

Osteolytic lesion of greater tuberosity in calcific tendinitis of the shoulder

HYPOTHESIS This study investigated tuberosity osteolysis, an uncommon and frequently misdiagnosed form of calcific tendinitis of the shoulder, and evaluated its effects on clinical and surgical outcomes. MATERIALS AND METHODS A total of 126 patients with calcific tendinitis studied with radiographs, ultrasound, and magnetic resonance images (MRIs) were divided into groups positive and negative for tuberosity osteolysis and treated by arthroscopy. Follow-up evaluation was at 2 years, using the Constant score. RESULTS Tuberosity osteolysis was associated with significantly lower Constant scores, both before and after surgical treatment. Clinical and imaging findings exhibited a significant correlation. A 100% correlation was found between arthroscopy and MRI findings of tuberosity osteolysis compared with 90% with radiographs. CONCLUSION Imaging and functional data indicate that calcific tendinitis of the rotator cuff with tuberosity osteolysis is a distinctive form of calcific tendinitis that should be considered in clinical and surgical practice. LEVEL OF EVIDENCE Level 2; Prospective non-randomized comparison prognosis study.

Osteoporotic pertrochanteric fractures can be successfully treated with external fixation

H ip fractures are the most severe of all fragility fractures. It has been calculated that more deaths are caused by hip fractures than by other common severe diseases such as cancer of the stomach or the pancreas1. Furthermore, regardless of the quality of surgical treatment, hip fractures remain a major cause of disability. The economic implications are clear. In the United States, hip fracture management already costs approximately

Biofilm extracellular-DNA in 55 Staphylococcus epidermidis clinical isolates from implant infections.

13.8 billion per year2. In Europe, the average acute hospital cost is approximately €25,000 per fracture and the total care cost is as much as 2.5 times higher3. Approximately 200,000 pertrochanteric fractures (AO/OTA fracture type A1 and A2) per annum occur in the United States alone4. It has been calculated by the United States Census Bureau that, by the year 2020, the average life expectancy will be eighty-two years for women and seventy-four years for men5. This longer life expectancy will be associated with a dramatic increase in the number of pertrochanteric fractures. The functional results of treatment of pertrochanteric fractures are often unsatisfactory. The mortality rate has been reported to be 18% in the first year following operative treatment6. The results are influenced by the inability of the implant to remain well fixed in osteoporotic bone during the time required for fracture-healing. Implant failure and loss of reduction, which often lead to fracture malunion, are frequent complications of osteoporotic pertrochanteric fractures. Because fracture stability is crucial for bone repair, poor bone quality remains a concern that must be given priority when the type of implant is being chosen7. The primary aim of surgical treatment is to obtain good fracture reduction and to maintain this reduction until sufficient stability is provided by the fracture callus. If stable …

Conservative management of rotator cuff tear.

Biofilm formation is broadly recognized as an important virulence factor in many bacterial species implicated in implant-related opportunistic infections. In spite of a long history of research and many investigative efforts aimed at elucidating their chemical composition, structure, and function, the nature of bacterial biofilms still remains only partly revealed. Over the years, different extracellular polymeric substances (EPS) have been described that contribute functionally and structurally to the organization of biofilms. Recently extracellular DNA (eDNA) has emerged as a quantitatively conspicuous and potentially relevant structural component of microbial biofilms of many microbial species, Staphylococcus aureus and S. epidermidis among them. The present study aims at comparatively investigating the amount of eDNA present in the biofilm of 55 clinical isolates of S. epidermidis from postsurgical and biomaterial-related orthopedic infections. Quantification of eDNA was performed by a non-destructive method directly on bacterial biofilms formed under static conditions on the plastic surface of 96-well plates.