Drilling through bone is a complex action that requires precise motor skills of an orthopedic surgeon. In order to minimize plunging and soft tissue damage, the surgeon must halt drill progression precisely following penetration of the far cortex. The purpose of this study was to create a low-cost and easy-to-use drilling simulator to train orthopedic residents in reducing the drill plunging depth. This prospective observational study was performed in the division of orthopedic surgery of a single tertiary medical center. The participants included 13 residents and 7 orthopedic specialists. The simulator consisted of a synthetic femur bone model and ordinary modeling clay, and the training unit consisted of a disposable plastic tube (∼US$14), clamps (∼US$58) and a power drill + drill bit (standard hospital equipment). Plunging depths were measured by the simulator and compared between orthopedic specialists, the 6 “senior residents” (3+ years) and the 7 “junior residents” during a training session. Measurements were taken again 2 weeks following the training session. Initially, the plunging depths of the junior residents were significantly greater compared to those of the orthopedic specialists (7.00 mm vs 5.28 mm, respectively, p < 0.038). There was no similarly significant difference between the senior residents and the orthopedic experts ([6.33 mm vs. 5.28 mm, respectively; p = 0.18). The senior residents achieved plunging depths of 5.17 mm at the end of the training session and 4.7 mm 2 weeks later compared to 7.14 mm at the end of the training session and 6 mm 2 weeks later for the junior residents. This study demonstrated the capability of a low-cost drilling simulator as a training model for reducing the plunging depth during the drilling of bone and soft tissue among junior and senior residents.

Background

Hallux valgus is a complex deformity of the first ray and forefoot, which can be surgically treated by different procedures and osteotomies. Preoperative planning includes antero-posterior and lateral plain films. The effect of weightbearing on the results of the standardized measurements is still the subject of debate.

Purpose: A retrospective analysis was conducted of 82 orthopedic injury cases sustained by IDF military personnel during the recent low intensity conflict (the second Palestinian uprising) which is characterized by many casualties and high availability of medical services and evacuation means.

Methods: Records of all orthopaedic combat casualties evacuated to two level–I trauma centers between November 2002 and October 2005 were reviewed. Data included demographics, evacuation time, location of wounds, wounding agents, associated injuries, early/ late care and complications.

Results: There were 51 patients (62%) injured by fire-arms and 31 patients (38%) by fragments and explosives. Mean evacuation time was 60 (± 22) minutes. The spectrum of injuries included soft tissue injury −43 (52%), open fracture−40 (48%), neurologic injury-19 (23%), vascular injury-7 (8%) and amputation −1 (1%). The most common procedure was debridement and irrigation (D& I) which was performed on 70 patients (85%). 19% of the open fracture patients underwent primary internal fixation.

The mean length of hospitalization was 5 days (range 1–36). A multivariate statistical analysis was done, and it was found that being included in more than one category stands alone as the only predictor for prolonged hospitalization. Infection rate was 9.7%, with length of stay being the only parameter associated with infection.

Conclusion: The recent low intensity conflict is an excellent example of early and aggressive trauma care, with an increased use of primary internal fixation. There is a high incidence of open fractures (48% of all extremity injuries) and a low amputation rate (1%). Multiple operative procedures have been shown to be successful at limb salvage, but are time intensive.

Background: To date, conventional freezing and cryopreservation of articular cartilage has had limited success due to the mechanical injury of cells resulting from uncontrolled ice crystal propagation. Frozen then thawed grafts show a total lack of viable articular cartilage cells and weakened matrix. Directional freezing using a precise velocity offers a new approach to the process of freezing, enabling cryopreservation of articular cartilage for long term storage and implantation.

Hypothesis: Cryopreservation of articular cartilage using directional freezing maintains significant chondrocyte viability and extra cellular matrix quality.

Study Design: Controlled Laboratory Study.

Methods: Articular Cartilage, collected from 20 porcine hind legs harvested immediately after slaughter, was transferred to the processing laboratory for cryopreservation and analysis. Cryopreservation was performed using a directional freezing system (MTG 1315). During preparation for freezing cryoprotectants were injected into the matrix using an array of 20 micron needles. Thirty 15mm cylindrical grafts were examined for cell viability and cell density using fluorescent and confocal microscopy and proteoglycan synthesis via ³⁵SO₄ uptake. Biomechanical assessment was performed on a second set of 9 grafts to determine the matrix instantaneous dynamic modulus of elasticity.

Results: Chondrocyte viability (53%±9%), viable cell density (18900 ± 4100 cell/mm³, 68%±5.7% viability) and ³⁵SO₄ uptake (59% compared to fresh control) were achieved. Biomechanical measures were mildly impaired (62%±5.2%) compared to fresh control due to the injection of cryoprotectants. In addition, chondrocyte viability in the cryopreserved allograft was preferentially maintained in the superficial zone. Similar results were obtained in human in-vitro studies.

Conclusion: Cryopreservation using directional freezing enables the preservation of viable cells within the collagen matrix. These cells are embedded in the supporting hyaline cartilage matrix with good mechanical stability. The behavior of cryopreserved cartilage after transplantation as indicated in sheep transplantations favors the generation of new, healthy hyaline cartilage during one year follow-up. The high percentage of viable cartilage cells, the quality of the matrix following freezing and thawing, and the ability to store these grafts in a hospital facility, are encouraging to meet the growing demand of such allografts in human cartilage repair procedures.

Effective pre-surgical preparation is an important step in limiting surgical wound contamination and prevention of surgical site infection. The purpose of this study is to evaluate bacterial skin contamination after surgical skin preparation in foot surgery prior to surgery and at the end of surgery, in order to determine if current techniques are satisfactory in eliminating harmful pathogens, and to compare the results of the cultures obtained pre and post operatively with infection rate.

Twenty consecutive patients scheduled for Hallux Valgus procedures were studied. Each lower extremity was prepared in the regular method with a two-step technique, Septal scrub followed by a Alcohol Chlorhexidine antiseptic solution. After preparation and draping, cultures were obtained at three locations: the hallux nailfold, first, second, third and fourth web spaces, and the anterior ankle (control). Prior to surgery, positive cultures were obtained from 80% of hallux nailfolds and 5% of web spaces. At the end of surgery, positive cultures were obtained from 80% of hallux nailfolds and 25% of web spaces. None of the controls had positive culture. 5% of all cases developed post operative infection.

Based on the findings of the current study, pre-surgical skin preparation with a two-step Septal scrub followed by a Alcohol Chlorhexidine antiseptic solution is not sufficient in eliminating pathogens in foot and ankle surgery. No statistical correlation was found between the results of the cultures obtained preoperatively or post operatively with post operative infection rate. The unique environment of the foot and its resident organisms probably plays a role in the higher infection rates associated with surgery of the foot. Better methods of preparing the surgical site should be searched for.

Scientific Background: Adult articular cartilage, critical to proper joint function, has minimal self-repair ability. No adequate repair technique exists for large defects.

Cryopreservation which is a process of deep-freezing of cells and tissues, enables the preservation of a high proportion of cells when the tissue is thawed and implanted.

Aim: To evaluate a novel method for cryopreservation of articular cartilage in the form of osteochondral sheep cylinders.

Materials and Methods: Osteochondral cylinders, 9mm diameter x 15mm length, were drilled from fresh cadaver sheep knee condyles. A bank of harvested cryo-preserved osteochondral cylinders was created. 17 sheep were used for transplantation. The thawed cylinders (allografts) were transplanted into the medial femoral condyle of the knee while the lateral femoral condyle received the fresh cylinder autograft as a control. The sheep were followed up for one year, following which in-vitro studies were performed to assess for articular cartilage viability.

Results: Clinically, histologically and radiologically there was almost 100% incorporation of allogenic osteochondral cylinders involving most of the weight-bearing area of the sheep knees.

Conclusion: Osteochondral cylinders can be successfully frozen and then transplanted into sheep knees with regeneration of knee function. Successful cryopreservation of human cartilage will be a major breakthrough in the treatment of cartilage lesions.

Introduction: Recent studies proved that Colchicine inhibits in-vitro proliferation of osteoblasts and osteosarcoma cells, and that Colchicine is non-selective mitosis inhibitor and selective inhibitor of mineralization. Aim: The aim of this study was to evaluate the effects of Colchicine (CO), given on a daily basis on healing process of bones. Materials and Methods: In a double blind prospective study, 3 groups of adult rats were checked. In each rat the left posterior tibia was broken. The study groups were treated with CO, one week before the fracture in one group, and on the fracture day in other group. The control group was not treated with CO at all. After six weeks the broken tibias were x-rayed and the radiographic union was compared between the groups. After the radiographic evaluation the bones were divided randomly to mechanical and histological evaluation. The union in each sample was estimated by 10 grades histopathological grading system. The mechanical tests were done, by checking the resistance to 3-points bending stress. Results: The results demonstrate signiþcant negative inßuence of chronic colchicine treatment on fracture healing. Radiographically, chronic treatment with colchicine reduced the union chance by 29. Clinically and mechanically, chronic treatment with colchicine reduced signiþcantly (p< 0.02) the callus strength. Pathological examination demonstrated mark reduction in the callus quality (p< 0.0001). Conclusions: In this study we proved that chronic treatment with colchicine reduce bone healing, and maybe the treatment policy (þxation methods, casting time, etc..) of skeletal injuries in colchicine treated patients, should be change.

Background: Heterotopic ossification is a common feature that follows total hip arthroplasty, and affects up to 70% of patients with clinical implications, such as pain and restricted hip movements. Previous clinical observation showed negligible heterotopic ossification in our patients who underwent total hip arthroplasty due to familial Mediterranean fever, and received colchicines on a daily basis.

Aims: To evaluate in vitro, in vivo and during clinical studies whether colchicines, given on a prophylactic daily basis to all total hip arthroplasty patients, was responsible for the negligible heterotopic ossification.

Methods: In vitro: cell lines of fibroblasts and osteoblasts were cultured with increasing concentrations of colchicines. Direct cell counts [3H]thymidine uptake, and mineralization were measure. In vivo: heterotopic ossification was induced in the thigh muscle of rabbits by injecting bone marrow. Animals were given colchicines, and X-ray radiographs, ultrasound the histological studies measured its effect on heterotopic ossification. Clinical study: Fifty-two patients admitted for total hip arthroplasty were randomly selected to receive colchicines on a daily basis, starting 10 days pre-operatively, and 6 weeks postoperatively. Clinical evaluation was made according to Harris Hip Score and heterotopic ossification according to Brooker classification.

Results: In vitro: colchicines was found to be a strong, nonselective inhibitor of cell proliferation, and an even greater inhibitor of tissue mineralization. In vivo: statistically significant reduction in the amount of hetero-topic ossification induced in the thigh muscle of rabbits was measured in the groups that received colchicines. Clinical study: Patients who received colchicines pre-operatively developed a negligible amount of hetero-topic ossification after total hip arthroplasty at 1-year follow-up without adversely affecting the Harris Hip Score.

Conclusions: Colchicine is a strong inhibitor of cell proliferation and tissue mineralization, and an effective means of reducing heterotopic ossification after total hip arthroplasty. These effects may be used in other bone-forming processes: after hip/pelvic trauma, head injury, and possibly in other bone-forming conditions.

Background: The few reported results of total hip arthroplasty (THA) in patients younger than 30 years of age involve mostly patients suffering from juvenile rheumatoid arthritis (JRA), indicate a high complication rate, and questionable durability.

Aim: We report our results of treatment of 56 patients who underwent total hip arthroplasty (71 THA operations) < 30 years of age at the time of surgery.

Methods: 56 patients who underwent total hip arthroplasty (71 THA operations) < 30 years of age at the time of surgery (mean 23.23 ± 4.31) were followed-up for a mean of 7.4 ± 3.79 years after surgery. Multivariant regression analysis indicated that although there was a variability of indications for surgery, only patient age at surgery, hospitalization time, and type of hip prosthesis (cementless vs. cemented) had a statistically valid influence on the final result, namely: Harris Hip Score (HHS) and complication rate.

Results: The final average HHS was 90.59 ± 9.36. Loosening of the cup in 11 of 71 and early traumatic dislocation of 5 of 71, accounted for the majority of complications.

Conclusions: These results indicated that THA is a durable, good treatment modality for young patients with disabling diseases that affect the hip joint.

Background: Childhood septic hip should usually be treated immediately by arthrotomy and antibiotic. Even if treated correctly, the affected hip may become osteoarthritic and functionally disabling.

Usually the literature is not in favor of THA in young patients, and the reports are on patients older than 32 years of age.

Aims: We present here a unique group of very young patients who suffered from early coxarthrosis due to septic hip in childhood, with an average age of 19.14 years at the time of the arthroplasty.

Methods: Seven patients who suffered from early coxarthrosis due to septic hip in childhood underwent total hip arthroplasty, with an average age of 19.14 years (range between 14 and 25 years) at the time of the arthroplasty.

Results: The Harris Hip Score (HHS) improved from a pre-operative mean of 58.43 to a post-operative mean of 94.14. The follow-up period ranged between 2 and 25 years, with an average of 8.14 years.

Conclusion: We conclude that THA in young people with early coxarthrosis due to septic hip in childhood provides good functional results.