Animal models of cartilage repair.

Cartilage repair in terms of replacement, or regeneration of damaged or diseased articular cartilage with functional tissue, is the 'holy grail' of joint surgery. A wide spectrum of strategies for cartilage repair currently exists and several of these techniques have been reported to be associated with successful clinical outcomes for appropriately selected indications. However, based on respective advantages, disadvantages, and limitations, no single strategy, or even combination of strategies, provides surgeons with viable options for attaining successful long-term outcomes in the majority of patients. As such, development of novel techniques and optimisation of current techniques need to be, and are, the focus of a great deal of research from the basic science level to clinical trials. Translational research that bridges scientific discoveries to clinical application involves the use of animal models in order to assess safety and efficacy for regulatory approval for human use. This review article provides an overview of animal models for cartilage repair. Cite this article: Bone Joint Res 2014;4:89-94.

The viability of cells obtained using the Reamer-Irrigator-Aspirator system and in bone graft from the iliac crest.

We hypothesised that cells obtained via a Reamer-Irrigator-Aspirator (RIA) system retain substantial osteogenic potential and are at least equivalent to graft harvested from the iliac crest. Graft was harvested using the RIA in 25 patients (mean age 37.6 years (18 to 68)) and from the iliac crest in 21 patients (mean age 44.6 years (24 to 78)), after which ≥ 1 g of bony particulate graft material was processed from each. Initial cell viability was assessed using Trypan blue exclusion, and initial fluorescence-activated cell sorting (FACS) analysis for cell lineage was performed. After culturing the cells, repeat FACS analysis for cell lineage was performed and enzyme-linked immunosorbent assay (ELISA) for osteocalcin, and Alizarin red staining to determine osteogenic potential. Cells obtained via RIA or from the iliac crest were viable and matured into mesenchymal stem cells, as shown by staining for the specific mesenchymal antigens CD90 and CD105. For samples from both RIA and the iliac crest there was a statistically significant increase in bone production (both p < 0.001), as demonstrated by osteocalcin production after induction. Medullary autograft cells harvested using RIA are viable and osteogenic. Cell viability and osteogenic potential were similar between bone grafts obtained from both the RIA system and the iliac crest.

Deep-vein thrombosis in high-energy skeletal trauma despite thromboprophylaxis.

We report the incidence and location of deep-vein thrombosis in 312 patients who had sustained high-energy, skeletal trauma. They were investigated using magnetic resonance venography and Duplex ultrasound. Despite thromboprophylaxis, 36 (11.5%) developed venous thromboembolic disease with an incidence of 10% in those with non-pelvic trauma and 12.2% in the group with pelvic trauma. Of patients who developed deep-vein thrombosis, 13 of 27 in the pelvic group (48%) and only one of nine in the non-pelvic group (11%) had a definite pelvic deep-vein thrombosis. When compared with magnetic resonance venography, ultrasound had a false-negative rate of 77% in diagnosing pelvic deep-vein thrombosis. Its value in the pelvis was limited, although it was more accurate than magnetic resonance venography in diagnosing clots in the lower limbs. Additional screening may be needed to detect pelvic deep-vein thrombosis in patients with pelvic or acetabular fractures.

Fracture stabilization of proximal tibial fractures with the proximal tibial LISS: early experience in Birmingham, Alabama (USA).

This study is a prospective evaluation of the Less Invasive Stabilization System (LTSS) for the treatment of high-energy tibial plateau and proximal tibial fractures treated between November, 1998 and June, 2000. Thirty-two patients sustained thirty-five acute fractures of the tibial plateau (25) or proximal tibia (10). These patients were injured primarily in blunt trauma accidents, with eighteen having multiple fractures, fifteen having ipsilateral extremity fractures, and eleven having major knee ligament injuries. Seventeen patients had open fractures. Thirty-four patients healed their fractures, with one developing a nonunion. Two patients developed infections, both following Type III open fractures. Final range of motion averaged 2 to 116 degrees. Alignment was well maintained, with no patient losing the alignment that was obtained in the operating room. The tibial LISS system worked well at stabilizing difficult fractures of the tibial plateau and proximal tibia with a low incidence of complications in this preliminary study with short-term follow-up.

Mechanical prophylaxis against deep-vein thrombosis after pelvic and acetabular fractures.

BACKGROUND: Deep-vein thrombosis is a common complication following pelvic and acetabular fractures. The hypothesis of this study was that pulsatile mechanical compression is superior to standard sequential mechanical compression for decreasing the prevalence of deep-vein thrombosis in patients with pelvic or acetabular fracture. METHODS: A prospective, randomized, blinded study of two methods of mechanical prophylaxis against deep-vein thrombosis was conducted. One hundred and seven patients were randomized into either Group A (fifty-four patients), in which a thigh-calf low-pressure sequential-compression device was used, or Group B (fifty-three patients), in which a calf-foot high-pressure pulsatile-compression pump was used. All patients underwent duplex ultrasonography and magnetic resonance venography. The two groups were comparable with regard to demographics, fracture type, fracture treatment, time from the injury to the prophylaxis, and patient compliance. RESULTS: Deep-vein thrombosis developed in ten patients (19%) in Group A, with seven (13%) having a large or occlusive clot and one (2%) having a documented pulmonary embolism. Deep-vein thrombosis developed in five patients (9%) in Group B, with two (4%) having a large or occlusive clot and none having a documented pulmonary embolism. Nine of the nineteen detected thromboses were in the deep pelvic veins. The difference in the prevalence of large or occlusive clots between the two groups demonstrated a trend but, with the numbers available, was not significant (p = 0.16). Increased patient age and the time elapsed from the injury to the surgery were found to be associated with higher rates of thrombosis. CONCLUSIONS: Pulsatile compression was associated with fewer deep-vein thromboses than was standard compression, with the difference representing a trend but not reaching significance with the number of patients studied.

A review of the treatment of hip dislocations associated with acetabular fractures.

Traumatic dislocation of the hip is an extremely severe injury. Although previously considered an uncommon lesion, it now is seen more often as a result of motor vehicle accidents. In most cases, dislocation of the hip is associated with fractures of the acetabulum, which ultimately can result in a higher incidence of complications than the complications observed in pure simple dislocations. Early recognition and prompt closed reduction of the dislocated hip constitute the cornerstone of proper treatment of this injury. Once the dislocation is reduced, definitive treatment of the acetabular fracture can be delayed to obtain a precise diagnostic evaluation. If surgical reconstruction of the acetabular fracture is indicated, it is done best in the first 10 days after the injury. A few patients in whom nonconcentric reduction, failed closed reduction, or impaired neurologic status occurs after reduction will require early open reduction and internal fixation of the fracture. Complications can be caused by the initial injury or by the treatment. Avascular necrosis of the femoral head, degenerative osteoarthritis, and heterotopic ossification are the main complications encountered in patients with unsatisfactory final results. Despite a perfect reduction of the hip dislocation and anatomic reduction of the acetabular fracture, a significant degenerative process of the hip is expected when the patient is assessed at long-term followup.

Functional outcome of patients with femoral head fractures associated with hip dislocations.

Fracture of the femoral head after hip dislocation is a relatively rare injury often associated with a poor functional outcome. Twenty-six patients who sustained femoral head fractures were evaluated using radiographs, clinical examinations, and a validated outcome scoring system. The Short Form-12 was used to assess functional outcome. Patients whose fractures were stabilized with 3-mm cannulated screws and washers had a poor functional outcome. When evaluated with an odds ratio analysis, the use of Kocher-Langenbeck posterior approach was associated with a 3.2 times higher incidence of the patients having avascular necrosis develop when compared with the Smith-Petersen approach. A literature review combined with the current series confirms that the principles of early reduction of hip dislocation, early stabilization, anatomic reduction of the fracture, and rigid fixation are critical principles to attain good results. The Brumback classification system provides superior differentiation of different fracture types when compared with the Pipkin classification. The Smith-Petersen anterior surgical approach is recommended for the majority of patients with femoral head fractures. Three-millimeter cannulated screws with threaded washers are contraindicated for use in stabilizing femoral head fractures, and should not be used in any joint because of dissociation between the screw and the washer.

A prospective evaluation of the timing of postoperative radiotherapy for preventing heterotopic ossification following traumatic acetabular fractures.

PURPOSE: Preoperative and immediate postoperative irradiation of traumatic acetabular fractures (TAF), although known to reduce heterotopic ossification (HO), can cause significant organizational and logistic difficulties. We sought to determine an acceptable time interval between surgery and radiation without compromising control, as well as to update our large experience and to further validate our treatment philosophy. METHODS AND MATERIALS: Beginning in June 1995, we began a prospective study, irradiating 152 patients on postoperative days 1, 2, or 3. There were also 17 patients delayed further secondary to medical difficulties. RESULTS: All patients treated since June 1995 received 700 cGy/1 fx. Fifty-eight patients received radiation within 24 hours of surgery, 41 within 2 days, 53 within 3 days, 13 within 4 days, and 4 were delayed further. Delaying irradiation for up to 4 days postoperatively caused no statistical increase in HO (p = 0.625). Of 263 patients in our retrospective cohort, HO occurred in 5.3% of patients who received irradiation versus 60% of patients who did not. CONCLUSION: In our prospective study, we noted no perceptible increase in HO with up to a 3-day interval between surgery and radiotherapy. This allows a more structured treatment schedule and allows the patient more time to heal and recover. Updated results from our overall series continue to demonstrate that adjuvant radiation decreases the incidence and severity of HO after TAF.

Acetabular fracture patterns: associations with motor vehicle crash information.

BACKGROUND: Motor vehicle crashes are the most common cause of acetabular fractures, which have been associated with significant morbidity and mortality. METHODS: To date, medical and collision information has been collected on 83 acetabular fracture patients treated at the University of Alabama at Birmingham's Level I trauma center. The fractures were grouped according to the Judet-Letournel classification scheme and investigated for correlation with age, sex, vehicle type, impact direction, and seat-belt use. RESULTS: The database included 41 women and 42 men with a combined average age of 32.8 years. Femoral shaft axis loading fractures correlated significantly with male sex, trucks, and frontal impacts. Greater trochanter loading fractures occurred statistically more frequently in side impacts. Women received a significant higher percentage of off-axis loading fractures, which were associated more in angled frontal impacts. CONCLUSION: Acetabular fracture type strongly correlated with impact direction, supporting the fracture mechanisms proposed by Judet and Letournel.

Controversies in acetabular fractures.

Open reduction and internal fixation has become the standard of care for the treatment of most displaced acetabular fractures. As surgical techniques have become refined, long term results of surgical fixation have improved. During the past 10 to 15 years, several controversies have surfaced in the orthopaedic literature regarding the treatment of acetabular fractures. The recent literature regarding acetabular fixation was reviewed. Controversies include the most efficacious surgical approach for complex acetabular fractures; the effectiveness of intraoperative sciatic nerve monitoring; the most effective method of prophylaxis against deep vein thrombosis; and the indications for and method of prophylaxis against heterotopic bone formation.

Prophylaxis of deep venous thrombosis after total hip arthroplasty by using intermittent compression of the plantar venous plexus.

A randomized, prospective, blinded study comparing the efficacy of prophylaxis of deep venous thrombosis by using (A) heparin-aspirin therapy, (B) intermittent pulsatile pneumatic-pump compression of the plantar venous plexus, or (C) both methods, was conducted in patients undergoing elective total hip replacement arthroplasty. Duplex ultrasonography was obtained in all 75 patients before surgery, at 1 week, and 2 weeks after surgery, to detect the presence or absence of deep venous thrombosis, with venograms confirming all positive results. Five of 25 patients in group A (heparin-aspirin) developed deep vein thrombosis. No deep venous thrombi were detected in groups B or C. One pulmonary embolus was detected in group A. The reduction in detectable deep venous thrombosis by the use of intermittent compression of the plantar venous plexus was significant. Wound drainage was decreased by 2 to 3 days (P < 0.05) in group B. It is concluded that, in this group of 75 consecutive patients, intermittent pulsatile compression of the plantar venous plexus was superior to heparin/aspirin pharmacologic prophylaxis for the prevention of deep venous thrombosis proximal to the calf.

Femur fractures in infants: a new therapeutic approach.

Fourteen patients with 16 femur fractures sustained between birth and 18 months of age were treated with a Pavlik harness rather than traditional casting methods. All of the fractures went on to stable union within 5 weeks. Eleven fractures have been followed-up for > 12 months, with a range of 12-30 months, and a mean of 20.1 months. All of the fractures healed in good alignment, with leg-length discrepancies < 1 cm. There have been no adverse results or complications as a result of treatment with the Pavlik harness to treat femur fractures, including fractures of the proximal and middle thirds of the femur; nonambulatory infants; < 4 months old at the start of treatment or small size in selected infants up to 6 months old; and shortening of < 2 cm. Advantages of the use of the Pavlik harness include ease of application without general anesthesia, minimal hospitalization, ease of reduction, ability to adjust the harness (and therefore the fracture alignment) if the reduction is lost, minimal cost, and ease of nursing, bonding with, and changing diapers on the infant.

Rupture of the triceps tendon associated with steroid injections.

Rupture of the triceps mechanism is an uncommon injury that has been recognized with increasing frequency in recent years. It has been proposed that such injuries commonly accompany fractures of the radial head and must be actively evaluated in the presence of such a fracture. We present a unique case of isolated rupture of the triceps tendon in an athlete who was lifting weights. This case was complicated by a history of olecranon bursitis that had been treated with numerous local steroid injections, as well as a history of anabolic steroid abuse. Both systemic steroids and local injections may predispose tendons to rupture. Triceps tendon ruptures may result in uniformly good to excellent results if recognized and treated surgically. This case also serves as a reminder of the risks of treating inflamed tissues with local steroid injections, especially in strength athletes who place high demands on their musculoskeletal structures. Finally, this case documents a second case of triceps mechanism rupture in an athlete who has abused anabolic steroids. A study by Hunter et al. suggests that oral steroid abuse may be associated with detrimental effects on the mechanical properties of connective tissue, demonstrating another negative effect of anabolic steroid use in athletes.

The prevalence of seropositivity for human immunodeficiency virus in patients who have severe trauma.

Patients who have severe trauma have been reported to have a substantially increased rate of seropositivity for human immunodeficiency virus when compared with the general population. We reviewed the records of 1226 consecutive Code-3 trauma patients who were treated at our institution in San Antonio, Texas, between 1987 and 1989. All of the patients had serum drawn to be tested for the human immunodeficiency virus. In contrast with previously published studies, only 0.8 per cent of these trauma patients were seropositive. There was no appreciable difference between the prevalence of seropositivity in patients who sustained blunt trauma and those who sustained penetrating trauma. Exposure to human immunodeficiency virus for medical personnel who care for trauma patients remains a concern, but the risk may be lower than previously reported.