Efficacy of treating segmental bone defects through endochondral ossification: 3D printed designs and bone metabolic activities.

Three-dimensional printing (3D printing) is a promising technique for producing scaffolds for bone tissue engineering applications. Porous scaffolds can be printed directly, and the design, shape and porosity can be controlled. 3D synthetic biodegradable polymeric scaffolds intended for in situ bone regeneration must meet stringent criteria, primarily appropriate mechanical properties, good 3D design, adequate biocompatibility and the ability to enhance bone formation.

Predictors of Osteoarthritis Development at a Median 25 Years After Anterior Cruciate Ligament Reconstruction Using a Patellar Tendon Autograft.

Background: Few studies have investigated the outcome ≥20 years after an anterior cruciate ligament reconstruction (ACLR) with a bone-patellar tendon-bone autograft, and there is a wide range in the reported rates of radiographic osteoarthritis (OA).

Purpose: To report on radiographic OA development and to assess risk factors of knee OA at a median 25 years after ACLR with a bone-patellar tendon-bone autograft.

Study Design: Case-control study; Level of evidence, 3.

Effect of Early Residual Laxity After Anterior Cruciate Ligament Reconstruction on Long-term Laxity, Graft Failure, Return to Sports, and Subjective Outcome at 25 Years.

Background: In spite of supposedly successful surgery, slight residual knee laxity may be found at follow-up evaluations after anterior cruciate ligament reconstruction (ACLR), and its clinical effect is undetermined.

Purpose: To investigate whether a 3- to 5-mm increase in anterior translation 6 months after ACLR affects the risk of graft failure, rate of return to sports, and long-term outcome.

Study Design: Cohort study; Level of evidence, 2.

Strength of side-to-side and step-cut repairs in tendon transfers: biomechanical testing of porcine flexor tendons.

The aim of the study was to compare side-to-side with step-cut repairs to determine how much of the width it is possible to remove and still keep the repair strong enough to start active mobilization. Porcine flexor tendons were used to create side-to-side, one-third step-cut and half step-cut repairs. There were 15 repairs in each group.

Autologous BPTB ACL Reconstruction Results in Lower Failure Rates Than ACL Repair with and without Synthetic Augmentation at 30 Years of Follow-up: A Prospective Randomized Study.

Background: The aim of this study was to compare the 30-year follow-up results after treatment of anterior cruciate ligament (ACL) ruptures with 3 different surgical procedures.

Methods: A total of 150 patients with acute rupture of the ACL who were managed between 1986 and 1988 were randomized into 1 of 3 open repair methods: acute primary repair (n = 49), acute repair with a synthetic ligament augmentation device (LAD) (n = 50), or reconstruction with an autologous bone-patellar tendon-bone (BPTB) graft with retention of the ACL remnants (n = 51). The 30-year follow-up included evaluation of clinical findings, the Tegner and Lysholm questionnaires, radiographic examination, and registration of revisions and knee arthroplasties.

Return to Play and Long-term Participation in Pivoting Sports After Anterior Cruciate Ligament Reconstruction.

Background: Rupture of the anterior cruciate ligament (ACL) is a common and feared injury among athletes because of its potential effect on further sports participation. Reported rates of return to pivoting sports after ACL reconstruction (ACLR) vary in the literature, and the long-term consequences of returning have rarely been studied.

Purpose: To examine the rate and level of return to pivoting sports after ACLR, the duration of sports participation, and long-term consequences of returning to pivoting sports.

Strength of Pulvertaft modifications: tensile testing of porcine flexor tendons.

The aim of the study was to present two new modifications of the Pulvertaft weave, allowing a higher number of weaves without the need for a longer overlap. The mechanical properties were measured and compared with the traditional technique. Forty-five pairs of porcine flexor tendons were randomized to a Pulvertaft repair with three weaves, a Double Pulvertaft and Locking Pulvertaft repairs.

Performance of bone cements: are current preclinical specifications adequate?

Background: Current specifications (standards) for preclinical testing of bone cements (ISO 5833: 2002, ASTM F451-99a) require simple mechanical testing after ageing for 24 h under dry conditions at 23 degrees C. Some bone cements have fulfilled the requirements in the specifications, and yet had inferior clinical results. Clinically, bone cements are subjected to complex loading patterns in a moist or wet environment at 37 degrees C.

Are inflatable nails an alternative to interlocked nails in tibial fractures?

Recently developed inflatable nails avoid reaming and interlocking screws in tibial fractures and reflect a new principle for stabilization of long bone fractures. We asked if the bending stiffness, rotational rigidity, or play (looseness of rotation) differed between an inflatable versus large-diameter reamed interlocked nails, and whether the maximal torque to failure of the two bone-implant constructs differed. In a cadaveric model, we compared the biomechanical properties with those of an interlocked nail in eight pairs of fractured tibial bones.

Should the galvanic combination of titanium and stainless steel surgical implants be avoided?

It is recommended that one should not combine different metals in orthopaedic devices. The least noble metal in such a galvanic coupling is more likely to corrode. However, some studies have failed to show increased corrosion when titanium and stainless steel are combined.

Time dependent mechanical properties of bone cement. An in vitro study over one year.

Changes in mechanical properties of bone cements over time are of clinical importance, but not well documented. Specifications for testing do not address the time factor. This study recorded changes in compressive properties and microstructure of one bone cement stored under simulated physiological conditions (water at 37 degrees C) from 20 min up to 1 year and in dry air at 37 degrees C for comparison.

Hip fracture implants increase serum metal levels.

Objective: Hip fractures are disabling accidents in the elderly. The purpose of this prospective study was to investigate systemic exposure to metals from hip implants used for fracture fixation.

Material And Methods: Serum levels of Cr, Ni and Mo in patients with compression hip screws (n = 22) or cervical fracture screws (n = 23) were measured by inductively coupled plasma mass spectrometry.

A sixteen-year follow-up of three operative techniques for the treatment of acute ruptures of the anterior cruciate ligament.

Background: This study compares three surgical procedures that we used in the past to treat ruptures of the anterior cruciate ligament: acute primary repair, acute repair augmented with a synthetic ligament-augmentation device, and acute repair augmented with autologous bone-patellar tendon-bone graft.

Methods: This is the third report on a group of patients who were randomized to the three different procedures between 1986 and 1988. There were fifty patients in each group.

Nickel contamination from an intravenous catheter used for infusion.

At the outset of a clinical research project involving metal analyses on patients receiving metal devices in conjunction with hip fractures, unexpected high concentrations of nickel were discovered in serum samples taken before surgery. The median nickel concentration in 30 patients was 4.6 microg/l (highest 19.

Long-term follow-up after primary repair of the anterior cruciate ligament: clinical and radiological evaluation 15-23 years postoperatively.

Introduction: We have previously reported results after 2-5 and 5-10 years follow-up of repair of acute anterior cruciate ligament (ACL) ruptures by suturing. Reports of results after more than 10 years are rare.

Materials And Methods: A total of 140 patients were operated on in the period 1975-1983 (age range 13-71 years, median 28 years) by the modified Palmer technique.

External fixation versus locked intramedullary nailing in tibial shaft fractures: a prospective, randomised study of 78 patients.

Introduction: We performed a prospective, randomised study to compare the Ex-fi-re external fixator (EF) with locked intramedullary (IM) nailing in tibial fractures. Only fractures without soft-tissue problems of importance were included.

Materials And Methods: Ex-fi-re is a unilateral, dynamic axial fixator with fracture reduction capabilities.

[Removal of osteosynthetic implants].

Background: Removals of fracture implants constitute a considerable share of orthopaedic operations and take up significant hospital resources. In the Norwegian basic fracture course, guidelines are given on indications for removal as well as minimum function time for implants. Indications for implant removal are, however, relative, and we wanted to study actual practice in this field in Norway.

Slippage between screwdriver and bone screw.

Cortical 3.5-mm stainless steel screws with hexagonal heads and corresponding screwdrivers from two manufacturers were investigated. Measurement of dimensions and torsional testing were done to study slippage between the screw and the driver bit.

Intramedullary nailing in humeral shaft fractures. Mechanical behavior in vitro after osteosynthesis with three different intramedullary nails.

The aim of this in vitro study was to compare the mechanical behavior of fixation by the Russell-Taylor nail with the more recent Polarus nail. Fixation with an experimental nail made from polyacetal polymer was also included in the study. Thirty humeri were fractured and randomized to receive one of the three nail types.

[Back pain--when both patients and physicians are in deep waters].

Background: Intraosseous pneumatocysts are rare and represent a benign condition. Such cysts can be an incidental finding described as a lytic process on plain X-rays. Computed tomography (CT) will confirm the diagnosis.

Dynamic traction for unstable fractures of the distal radius.

We have designed a flexible distracter through which dynamic traction is applied to fractures of the distal radius. The distraction is maintained during flexion and extension as well as radial and ulnar deviation. The results in 30 patients showed that the majority of the fractures maintained reduction during the period of dynamic traction.

Lateral ligament injuries of the knee.

Between 1982 and 1994 28 patients were treated for acute lateral knee ligament injuries; 25 patients, with a median age of 25.5 (range 16-75) years at injury, appeared for follow-up. Seven patients had isolated injury of the lateral collateral ligament/capsular structures, the remaining 19 patients had concomitant ligament injuries in the knee.

Mechanical effects of different localization of the point of entry in femoral nailing.

Twenty pairs of human femora were reamed alternatively on the right or left side, with the opposite side serving as the unreamed control. The fossa piriformis (group I) or tip of the greater trochanter (group II) were chosen for introduction of the intramedullary reamer (Howmedica type). The femora were tested in vertical compression in a MTS mechanical testing machine until failure.

Closed reduction and external fixation of unstable fractures of the distal radius.

The anatomical and functional outcome and complications after closed reduction and external fixation of unstable fractures of the distal radius were reviewed in 29 patients. The fractures were reduced by longitudinal traction and closed manipulation under fluoroscopic control, and the reduced position was retained by a standard half-frame Hoffmann external fixator for six to eight weeks. The mean follow-up time was four (3-7) years.