Long term results of bone-patella-tendon-bone ACL reconstruction.

Background: To assess outcomes of bone-patella-tendon-bone ACL-reconstruction at 18 years follow-up.

Material And Methods: Outcome measures included the IKDC clinical examination form and clinical scores. Radiographs were analyzed to determine the grade of osteoarthritis.

Biomechanical effectiveness of an arthroscopic posterior bankart repair versus an open bone block procedure for posterior shoulder instability.

Background: The most effective surgical treatment for traumatic posterior shoulder instability remains unclear.

Hypothesis: An arthroscopic posterior Bankart repair is as effective as an open posterior bone block-capsulorrhaphy procedure regarding the restoration of humeral displacement with posterior and inferior forces.

Study Design: Controlled laboratory study.

Biomechanical stability of an arthroscopic anterior capsular shift and suture anchor repair in anterior shoulder instability: a human cadaveric shoulder model.

It was hypothesized that an arthroscopic Bankart repair with suture anchors supplies sufficient anterior shoulder stability, which cannot be improved by an additional capsular shift. In an experimental biomechanical human cadaver study, we tested ten fresh human cadaver shoulders in a robot-assisted shoulder simulator. External rotation and glenohumeral translation were measured at 0 degrees and 80 degrees of glenohumeral abduction.

A rotating inlay decreases contact pressure on inlay post after posterior cruciate substituting total knee arthroplasty.

Background: The post/cam mechanism of posterior cruciate substituting total knee arthroplasty, which is intended to achieve maximum range of flexion, offers the risk of failure due to mechanical overload. The purpose of this in vitro study was to investigate load and contact pressure on the inlay post of posterior substituting knee prosthesis with different designs.

Methods: Isokinetic extension/flexion motions of seven fresh frozen left knee specimens were simulated dynamically in a specially designed knee simulator with an extension moment of 31 Nm.

[External rotation osteotomy of the humerus for treatment of external rotation deficit in palsies].

Objective: Aim of the procedure is shifting the arc of shoulder rotation for an improved external rotation, reaching a physiological elbow flexion without striking of the lower arm against the thorax; improvement of the activities of daily living because guidance of the hand to the face is possible without any simultaneous evasive movements of the shoulder.

Indications: Palsy of infraspinatus and teres minor muscles after complete neurosurgical therapy (neurolysis, reconstruction of the brachial plexus), which leads to loss of external rotation and an internally rotating posture of the arm. Elbow flexion is hindered because of striking of the lower arm against the thorax, simultaneous abduction and foreward flexion is necessary to guide the hand to the face.

[Modified technique of trapezius transfer to improve function in brachial plexus palsy].

Objective: Increase of shoulder stability. Elimination of inferior subluxation of the humeral head. Increase of active abduction.

Characterized chondrocyte implantation results in better structural repair when treating symptomatic cartilage defects of the knee in a randomized controlled trial versus microfracture.

Background: As the natural healing capacity of damaged articular cartilage is poor, joint surface injuries are a prime target for regenerative medicine. Characterized chondrocyte implantation uses an autologous cartilage cell therapy product that has been optimized for its biological potency to form stable cartilage tissue in vivo.

Purpose: To determine whether, in symptomatic cartilage defects of the femoral condyle, structural regeneration with characterized chondrocyte implantation is superior to repair with microfracture.

[Reconstruction of the medial patellofemoral ligament by tunnel transfer of the semitendinosus tendon].

Objective: Stabilization of the patella by reconstruction of the medial patellofemoral ligament.

Indications: Chronic recurrent lateral dislocation or subluxation of the patella. Habitual lateral dislocation of the patella.

The influence of patellar bracing on patellar and knee load-distribution and kinematics: an experimental cadaver study.

The aim of this study was to analyze the biomechanical consequences of patella bracing in order to evaluate possible mechanisms supporting its clinical application. The hypothesis is that the patellar bracing reduces patellofemoral pressure by influencing patellar and knee kinematics, and load distribution. Physiologic isokinetic knee extension motions were simulated on ten human knee cadaver specimens using a knee kinematic simulator.

Arthroscopic meniscal repair with bioresorbable implants.

Objective: Restoration of the shape and function of a torn meniscus.

Indications: Complete or large incomplete longitudinal tear of the medial and lateral meniscus close to the base, large flap tear, so-called bucket-handle tear.

Contraindications: Degenerative meniscal tissue.

Dynamic measurement of patellofemoral contact pressure following reconstruction of the medial patellofemoral ligament: an in vitro study.

Background: Surgical reconstruction of the medial patellofemoral ligament used to stabilize the patella against lateral dislocation may concomitantly produce alteration of the patellofemoral contact pressure distribution. Two different tendon transfer techniques of reconstructing the medial patellofemoral ligament, one dynamic and one static, as well as a proximal soft tissue realignment of the patella were investigated.

Methods: Eight human knee specimens were mounted in a kinematic knee simulator and isokinetic extension motion was simulated.

Influence of an infrapatellar fat pad edema on patellofemoral biomechanics and knee kinematics: a possible relation to the anterior knee pain syndrome.

Introduction: An edema of the infrapatellar fat pad following knee arthroscopy or in case of chronic anterior knee pain syndrome is suspected to increase the patellofemoral pressure by a modification of the patellofemoral glide mechanism. The study was performed to evaluate this hypothesis.

Materials And Methods: Isokinetic knee extension from 120 degrees of flexion to full extension was simulated on 10 human knee cadaver specimens (six males, four females, average age at death 42 years) using a knee kinemator.

In vitro measurement of patellar kinematics following reconstruction of the medial patellofemoral ligament.

This study compares the effects of two different techniques of medial patellofemoral ligament (MPFL) reconstruction, and proximal soft tissue realignment on patellar stabilization against lateral dislocation. Eight human cadaver knee specimens with no radiological pathomorpholgy on a straight lateral view, contributing to patellofemoral instability, were mounted in a kinematic knee simulator and isokinetic extension was simulated. Patellar kinematics were measured with an ultrasound positioning system (zebris) while a 100 N laterally directed force was applied to the patella.

Distribution of substance-P nerves inside the infrapatellar fat pad and the adjacent synovial tissue: a neurohistological approach to anterior knee pain syndrome.

Introduction: The purpose of the study was to determine the distribution and number of nerves inside the infrapatellar fat pad and the adjacent synovium, in particular with regards to nociceptive substance-P nerves.

Materials And Methods: The infrapatellar fat pad of the knee was resected from 21 patients (4 male, 17 female, mean age 69 years) during the course of standard total knee arthroplasty operations performed in our clinic. The fat pad was dissected into five standardized segments, fixed in formalin and embedded in paraffin.

Infrapatellar fat pad pressure and volume changes of the anterior compartment during knee motion: possible clinical consequences to the anterior knee pain syndrome.

This biomechanical study was performed to measure tissue pressure in the infrapatellar fat pad and the volume changes of the anterior knee compartment during knee flexion-extension motion. Knee motion from 120 degrees of flexion to full extension was simulated on ten fresh frozen human knee specimens (six from males, four from females, average age 44 years) using a hydraulic kinematic simulator (30, 40, and 50 Nm extension moment). Infrapatellar tissue pressure was measured using a closed cell sensor.

Primary stability of shoulder arthrodesis using cannulated cancellous screws.

There are no biomechanical studies available concerned with the primary stability of shoulder arthrodesis. The aim of our biomechanical investigations was to ascertain a minimal material combination with high primary stability for shoulder arthrodesis. For that purpose, the primary stability of 6 different forms of screw arthrodesis was investigated under the stress of abduction, adduction, anteversion, and retroversion.

Shoulder arthrodesis: indications, technique, results, and complications.

Complications after shoulder arthrodesis are frequent. Through results and comparisons with the literature, the presented article analyzes the correlation of complications with the specific operative techniques, indications, and postoperative treatment. Between 1964 and 2001, a total of 43 cases of shoulder arthrodesis (13 screw and 30 plate arthrodeses) were performed and then analyzed after a mean of 6.

Risk evaluation of thermal injury to the cervical spine during intradiscal laser application in vitro.

Objective: We aimed to investigate temperature distribution during laser and its possible thermal damage to the neurovascular structures.

Background Data: Percutaneous laser disc decompression (PLDD) is now being performed as a minimally invasive intradiscal technique for the operative therapy of non-sequestered herniated cervical discs. As yet, no experimental basic research has been reported with regard to temperature rise and distribution in the cervical region during laser radiation.

Biomechanical and kinematic influences of a total infrapatellar fat pad resection on the knee.

Background: This biomechanical study was performed to evaluate the consequences of total infrapatellar fat pad resection on knee kinematics and patellar contact pressure.

Hypothesis: Resection of the infrapatellar fat pad produces significant changes in knee kinematics and patellar contact pressure.

Study Design: Biomechanical cadaveric study.

Reconstructive operations for the upper limb after brachial plexus palsy.

Limited function due to paralysis following brachial plexus lesions can be improved by secondary operations of the bony and soft tissue. Between April 1994 and December 2000, 109 patients suffering from arm-plexus lesions underwent a total of 144 reconstructive operations guided by our concept of integrated therapy. The average age at the time of surgery was 32 years (range: 15-59).

Clinical results of arthroscopic meniscal repair using biodegradable screws.

This study was performed to assess the clinical results of meniscus refixation using biodegradable Clearfix meniscal screws. Between July 1999 and June 2001 this technique was performed on 65 patients, of whom 60 (27 women, 33 men; 92%) were followed up by clinical examination after an average of 18 months (range 8-34). The average age of the patients at the time of surgery was 30 years (15-58).

The influence of limited postoperative weight-bearing on the outcome of drilling in osteochondritis dissecans tali.

Introduction: This prospective study was performed to assess the influence of limited weight-bearing on the outcome of osteochondral drilling in the treatment of an osteochondritis dissecans tali.

Materials And Methods: Of a total of 85 patients, 68 (80%; 37 male, 31 female, average age 28 years) were followed up after open or arthroscopic drilling between July 1990 and March 2000. The total outcome of 6 weeks limited postoperative weight-bearing (n=26) was compared with the outcome of 12 weeks limited weight-bearing (n=42).

The value of knee arthroscopy in patients with severe radiological osteoarthritis.

Background: This study was performed to assess the value of knee arthroscopy in patients with radiological signs of severe osteoarthritis.

Methods: A total of 104 patients (50 men, 54 women, average age 60 years) with radiological knee osteoarthritis grade III/IV were followed up after knee arthroscopy between May 1989 and November 1996. The average follow-up time was 5.

Arthroscopic anterior shoulder stabilization: combined multiple suture repair and laser-assisted capsular shrinkage.

The results of laser-assisted capsular shrinkage (LACS) in combination with arthroscopic refixation of the capsulolabral avulsion are compared to those of an arthroscopic Bankart repair alone. In a prospective study, an arthroscopic LACS in combination with a multiple suture capsulolabral refixation according to Caspari and Savoie (Am. J.

Biomechanical properties of commonly used autogenous transplants in the surgical treatment of chronic lateral ankle instability.

The purpose of this study was to evaluate the biomechanical properties of commonly used autogenous transplants for the surgical stabilization of chronic lateral ankle instability. We dissected the transplants (peroneus longus, peroneus brevis, Achilles and plantaris tendon, periosteal flap, fascia, corium) and the anterior talofibular ligament from 13 fresh anatomic specimens. After laser-assisted measurement of the transplant diameter, we assessed their biomechanical properties with a universal testing device.