PubMed Health⌕ Search

Biomedical subjects

R Schabus

Publications and source records attributed to R Schabus.

At least 19 recordsLinked to original sources
PubMed2002

Rupture of the extensor pollicis longus tendon after wrist trauma.

In the period of 1976 to 1997 our clinic treated 33 patients after Colles fracture with ruptured extensor pollicis longus tendon. The occurrence of functional loss was observed after the trauma in 3 to 9 weeks. In 30 cases the surgical treatment of extensor indicis proprius tendon, in 2 cases a direct suture of the ruptured tendon was performed as a primary repair and in one patient a palmaris longus interposition was utilised.

Adult↗
PubMed2001

Light and electron microscopic study of stress-shielding effects on rat patellar tendon.

In this second part of our study, the histomorphologic changes occurring in the patellar tendon (PT) of rats after sole stress-shielding were evaluated. In seven adult albino rats, both PTs were exposed by straight skin incision and then stress-shielded on one side by a cerclage, while the contralateral PT served as the sham-operated control. One animal died after the operation and was used as a negative control. After 10 weeks of otherwise unrestricted motion, the rats were killed, and the histomorphology of all PT specimen pairs compared by light and transmission electron microscopy. Light microscopy showed mid-portion thickening and irregularity of collagen bundles in the stress-shielded tendons. Intense remodelling was demonstrated by increased cellularity and vascularity, as well as by enrichment in acidic proteoglycans. Ultrastructural evaluation and morphometry revealed a predominance of large diameter (peak between 180 and 260 nm) collagen fibrils in the sham-operated controls, while in the stress-shielded tendons the number of apparently new, small-diameter (peak between 40 and 60 nm) collagen fibrils increased (up to 77% per cross-sectional field of view). The difference in peak diameters was statistically significant (p < 0.0005). This rat model demonstrated that sole stress-shielding not only causes biomechanical alterations, but also intense tissue remodelling and significant morphological changes in the collagen fibrils in the patellar tendon, comparable to so-called 'ligamentization' in experimental and clinical patellar tendon grafts for anterior cruciate ligament reconstruction.

Animals↗
PubMed2000

Mechanical properties of a rat patellar tendon stress-shielded in situ.

The effects of stress deprivation on the mechanical properties of the patellar tendon (PT) were studied using 14 albino rats. The PT was stress-shielded with cerclages on one side, while the contralateral patellar tendon served as a sham-operated control. After 10 weeks, paired load-strain as well as load-relaxation experiments were performed (11 and 3 specimen pairs, respectively). Mechanical tests showed, irrespective of the cerclage material used, that strain was increased significantly after stress-shielding (P < 0.02). The time constant significantly decreased in the stress-shielded specimens under 5 N loads, which may be considered 'physiological'. Tissue remodeling might explain the observed changes in the viscoelastic behaviour of the stress-shielded tendons. Loading, even in the physiological range of normal daily activity, may lead to an elongation of previously stress-shielded tendons or ligaments and consequently alter the behaviour of a joint.

Animals↗
PubMed1999

Cyclops and cyclopoid formation after anterior cruciate ligament reconstruction: clinical and histomorphological differences.

Prospectively, 119 patients were pursued clinically and by follow-up-arthroscopy for the occurrence of a "cyclops syndrome" after ACL reconstruction with a patellar tendon autograft, augmented by LAD. Twenty-one patients showed nodular formations. Ten of these (group 1) developed early clinical evidence of a "cyclops syndrome" with a mean extension deficit of 19 degrees before follow-up-arthroscopy, on average 5.9 months after the index operation. The nodular formations found and excised during débridement had a hard consistency. Histomorphological undecalcified microtome section evaluation of six specimens revealed fibrocartilagineous tissue with active bone formation in the center. The other 11 patients showed no clinical symptoms (group 2). A similar but soft nodulous scar formation was detected at follow-up-arthroscopy, on average 9.5 months after the index operation. Histomorphologically these so-called "cyclopoid" formations were only built-up fibrocartilagineous islands surrounded by granulation tissue. Neither remnants of tendon graft fibers nor old bone particles were found in specimens of either group. It can be concluded that both the hard cyclops and the soft "cyclopoid" are de novo scar formations.

Adolescent↗
PubMed1999

Anterior cruciate ligament reconstruction alters the patellar alignment.

Although there are many articles dealing with anterior cruciate ligament (ACL) reconstruction, there are none dealing with the possibility of changes of the patellofemoral alignment after these procedures. Forty-six patients were evaluated preoperatively and 1 year postoperatively, after undergoing intra-articular ACL reconstruction, for changes of the patellofemoral alignment. Patella-tilt and congruence angles were measured on tangential view radiographs that were taken in the supine position. Analysis of covariance was performed and revealed a significant change of the congruence angle 1 year postoperatively. The patella-tilt did not change. One year postoperatively, the patella shifted on average 5 degrees medially after ACL grafting. It can be deduced that anterior knee pain after ACL reconstruction could be caused by distinct changes in the patellofemoral alignment.

Adult↗
PubMed1998

[Late lesion of the brachial plexus after clavicular fracture].

Neurological complications in clavicle fractures are rare. As a primary lesion, it is caused by the trauma itself. More often however, the neurological symptoms develop later by large callus formation that encroach on the costoclavicular space. A case report is presented of delayed injury to the brachial plexus due to clavicular fracture with non-union and callus formation.

Adult↗
PubMed1998

No benefit of bracing on the early outcome after anterior cruciate ligament reconstruction.

Forty patients were prospectively investigated to evaluate the effects of bandaging after reconstructive surgery of the anterior cruciate ligament (ACL). For the 6 weeks of the postoperative course, the operated knee was bandaged in 20 patients (group A) and braced in the other 20 patients (group B). The isokinetic torque for extension and flexion (Cybex) and the range of motion (ROM) were investigated after 6, 12, 24 and 52 weeks postoperatively. At 24 weeks and 1 year postoperatively the stability of the knee joint (KT-1000) as well as the clinical outcome ('Orthopädische Arbeitsgemeinschaft Knie') were evaluated. No statistically significant differences between the two groups were found for the extension and flexion strengths. Free ROM was achieved significantly earlier in group A than in group B. No statistically significant differences regarding the stability of the operated knee joint nor the early outcome were found between the two groups. This study demonstrated that the renunciation of using a brace had no adverse effect on the early outcome with respect to stability and function. On the contrary, bracing seems not to be mandatory after ACL reconstruction when the central third of the patellar tendon is used.

Adolescent↗
PubMed1998

Twisting of patellar tendon grafts does not reduce their mechanical properties.

The purpose of this study was to investigate whether the twisting of a patellar tendon (PT) graft improves or reduces its mechanical properties. Twenty-seven pairs of 10 mm cadaveric PT grafts were tested at a strain rate of 10% min(-1). For each pair, the left specimen served as an unmanipulated control while the right specimen was either left untwisted, twisted + 90 degrees, or twisted - 90 degrees. All avulsion failures were excluded from the data analysis, focusing only on pure in-substance tendon ruptures. Higher ultimate load values than previously reported were obtained for both the twisted and untwisted specimens, without a statistical significant difference between the two. The values obtained for the left and right specimens from Group A were 4014+/-319 and 3973+/-245 N, from Group B 3613+/-207 and 3891+/-14 N, and from Group C 3997+/-278 and 4415+/-507 N, respectively. Stiffness and failure strain were not influenced by the twisting. Neither the presence of a twist, nor the direction of the twist were found to increase the ultimate load of the 10 mm cadaveric patellar tendon graft. Therefore, recommendation for twisting cannot be assessed to its mechanical properties.

Adult↗
PubMed1998

Shortening of the patellar tendon after anterior cruciate ligament reconstruction.

In this prospective study, patellar height changes were investigated after anterior cruciate ligament (ACL) reconstruction with a mean follow-up of 22.4 months. A total of 114 patients were included. Fifty-two patients (group A) were treated by multiple suture repair, 27 patients (group B) underwent acute ACL reconstruction, and 35 patients (group C) underwent ACL reconstruction > or =6 weeks after injury with a patellar tendon graft. The patellar vertical height ratios (VHR) were evaluated preoperatively (VHR 1), 6 months postoperatively (VHR 2), and at follow-up (VHR 3). For the studied questions, the following answers were obtained: (1) The change of the patella height was the same in all three groups (i.e., disregarding the different surgical procedures). (2) The time elapsed between injury and ACL reconstruction did not influence the shortening of the patellar tendon. (3) Women showed a more pronounced shortening of the patellar tendon than did men. (4) A significant shortening of the patellar tendon occurred in 30% of our patients, and the process of shortening was finished 6 months postoperatively. (5) Anterior knee pain was present in 27.2% of our patients and occurred significantly more often after patellar tendon graftings. (6) Age had no influence on the changes of the patellar height.

Adult↗
PubMed1998

Epidermoid cyst after arthroscopic knee surgery.

Eleven years after an arthroscopic procedure, a benign tumor of the knee located beneath the scar where the outflow canula was placed was excised. Histomorphological evaluation determined the diagnosis of an epidermoid cyst. This is the first case reported in the literature of an epidermoid cyst occurring after an arthroscopic operation. The previous epidermoid cysts reported were found after trauma or after dermal grafting for epithelium implantation.

Adult↗
PubMed1998

Patellar alignment evaluated by MRI.

We analyzed the congruence of the articular cartilage surfaces and the corresponding subchondral bone in the patellar joint. 20 volunteers underwent MRI investigations of the right patellar joint in 20 degree and 45 degree flexion in the axial plane. The sulcus, congruence, and lateral patellofemoral angles, measured on MRI slices centered through the midtransverse patella, were recorded. In 20 degree and 45 degree knee flexion, the bony sulcus and lateral patellofemoral angles were significantly different from the respective cartilagineous angle. We conclude that 1) measurement of the bony sulcus and lateral patellofemoral angles does not allow conclusions about the articular cartilage surface and its thickness, 2) the bony congruence angle corresponds well to the articular cartilage surface as an indicator of patellar centralization.

Anthropometry↗
PubMed1997

Braided polypropylene augmentation device in reconstructive surgery of the anterior cruciate ligament: long-term clinical performance of 594 patients and short-term arthroscopic results, failure analysis by scanning electron microscopy, and synovial histomorphology.

Long-term clinical results and short-term arthroscopic and microscopic findings from two augmented reconstruction procedures for the ruptured anterior cruciate ligament are reported. The braided polypropylene ligament augmentation device (Kennedy model) was used with temporary double-end fixation in 279 patients to augment the attachment of the anterior cruciate ligament after acute proximal rupture and in 315 patients to augment a bone-tendon-bone autograft, mainly after chronic instability. Check arthroscopy was performed and the metal fixation hardware was removed after a mean of 11 months. Of the 569 patients evaluated, 101 partial or total breakages of the ligament augmentation device were found. Together with nine breakages detected late in the follow-up period, 110 (19.3%) failures were found. Most of these failures were accompanied by effusion that was immediately alleviated when the failed device was removed. No generalized synovitis was visible. Scanning electron microscopic analysis of 24 retrieved failed ligament augmentation devices showed fatigue to be the principal failure mode, together with local abrasion at the fracture. Synovial biopsies were taken during arthroscopy in 84 patients with and without ligament augmentation device-failure who had given informed consent, and histological evaluation revealed that in 21 patients, chronic but no acute synovial inflammation was found, and wear particles could be identified in foreign body cells in 17. Statistically, the presence of chronic synovitis was predicted neither by wear particles and foreign body cells nor by abrasion or fatigue failure of the ligament augmentation device. Irrespective of the failures, for which ligament augmentation device removal is recommended, in the final Orthopaedische Arbeitsgemeinschaft Knie evaluation (after a mean of 6.2 years), excellent and good clinical results were found in 83.6% of all 594 patients.

Adolescent↗
PubMed1994

Measurement of stress-strain relationship and stress relaxation in various synthetic ligaments.

In an experimental study various synthetic augmentation devices for knee ligament surgery were tested in a servo-mechanical universal tensile testing machine under uniaxial loading. Two tests were done to elucidate the mechanical behaviour: stress relaxation and stress-strain relationship. Regarding the point of failure or rupture, the strongest ligament was the Trevira at 1800 N, followed by the 8-mm-wide Kennedy LAD at 1720 N. At a working load of 500 N the Gore-tex band, the Trevira, and the Kennedy-LAD stretched by between 2% and 3%. For synthetic augmentation in repair of proximally ruptured anterior cruciate ligaments we recommend a synthetic ligament that reaches failure point at a load of more than 1000 N with an alteration in length of less than 5%. Otherwise, stress protection of the biological reconstruction in full extension will be impossible. The requisite criteria were fulfilled by the Trevira, Kennedy-LAD and Gore-tex synthetic ligaments.

Biomechanical Phenomena↗
PubMed1994

Opening wedge osteotomy for malunion of the distal radius with neuropathy. 13 cases followed for 6 (1-11) years.

13 patients with malunion of the distal radius after Colles' fractures and electroneurographically verified median nerve compression underwent an opening wedge osteotomy without a simultaneous release of the transverse carpal ligament. 12 patients had reduction of the typical night pain with normal or almost normal sensibility within the first 2 months. In 1 patient a release of the carpal ligament was necessary after 6 months. 6 years postoperatively all patients had acceptable wrist function with normal function of the median nerve in all but one.

Adult↗
PubMed1994

[Treatment of spinal injuries].

The treatment of spinal column injuries relies on the well founded knowledge in functional spinal anatomy. An exact diagnosis is based on a thorough clinical and neurological examination. X-rays, CT-scan and eventually an MRI examination. A fracture classification is imperative for further conservative and operative treatment. Fractures and fracture dislocations of the thoracic and lumbar spine are generally classified in groupings based on the three column theory of Dennis. The whiplash injury is the most common soft tissue injury of the cervical spine. The initial therapy of this trauma intends to achieve a fast reduction of pain and inflammatory tissue reactions. Of all fractures regarding the human beings the spinal column is affected in about one percent. The most common fracture localisation is the thoraco-lumbar spine. Fractures of the atlas (Jefferson fracture) and odontoid fractures type Anderson I and Anderson III are usually treated by a halo west for 8-12 weeks. Odontoid fractures type Anderson II are stabilised by screw fixation. Fractures below C 2 require an operative stabilisation in most cases. Ventral, dorsal and combined ventral-dorsal spondylodeses are performed. Fractures of the thoracic and lumbar spine are treated conservatively in about 80-90% of our cases. Fractures of the upper thoracic spine usually require no external fixation, functional treatment is possible. Fractures below Th 11 are treated by reduction and casting for 12 weeks. Within the last 15 years the operative treatment of these fractures continually increased. Dorsal stabilisation with pedicle implants prevailed in the last years. The aftercare of spinal trauma patients consists in an intensive physical therapy for at least three months.

Diagnostic Imaging↗
PubMed1993

A new approach to the subacromial space. Technique and 2-year results in 28 rotator-cuff repair cases.

We present a new approach to the subacromial space, consisting essentially of an osseous detachment of the deltoid muscle from the anterior and lateral rim of the acromion including the osseous origin of the coraco-acromial ligament. After acromioplasty and an eventual reconstruction of a torn rotator cuff, Kessler-sutures provide stable transosseous repair of the deltoid muscle. This method generally allows immediate active shoulder motion. 25 of 28 patients with rotator cuff ruptures alone or in combination with an impingement syndrome had good results according to the UCLA-score 2 years postoperatively. No serious complications regarding the function of the deltoid muscle or any failure of the accompanying acromioplasty occurred.

Acromion↗
PubMed1993

Synthetic augmented repair of proximal ruptures of the anterior cruciate ligament. Long-term results of 66 patients.

The long-term results (five-to eight-year follow-up evaluation) of 66 patients with high proximal ruptures of the anterior cruciate ligament (ACL) who were treated operatively are presented in a retrospective and uncontrolled study. Technique of surgery was the reinsertion of the ACL in a multiple suture loop technique, augmented with Kennedy-LAD (ligament augmentation device) on over the top route in temporary double-end fixation. This technique was used in patients with proximal rupture of the anterior cruciate ligament found at arthroscopy. In the follow-up as well as in instrumented measurement, 97% of the knee joints have normal joint laxity. According to the evaluation sheet designed by the Orthopädische Arbeitsgemeinschaft Knie (OAK), excellent or good results were found in 86% of the patients. Nine percent had limited range of motion. The ACL reconstruction technique allowed 75% of the patients to regain their preinjury sports activity level. The potential advantages of synthetic augmented reinsertion of the ACL are anatomic reconstruction without destruction of other anatomic structures as grafts; securing early rehabilitation with weight bearing of the operated limb depending on individual pain tolerance; and presenting excellent long-term results of normal joint laxity.

Adolescent↗