Search PubMed⌕ Search

Biomedical subjects

A B Imhoff

Publications and source records attributed to A B Imhoff.

53 records · Page 3Linked to original sources

[Combined anterior cruciate ligament and posterior cruciate ligament injury--technique and results of simultaneous arthroscopic reconstruction].

Simultaneous ACL and PCL ruptures are rare but serious injuries resulting in distinct instability of the knee joint followed by an early degenerative arthritis. This combined trauma, which is often accompanied by additional ligament lesions, originates from a knee dislocation. While the conservative treatment of this complex instability is abandoned, the operative procedures are not yet standardised. The timing of the cruciate ligament reconstruction depends on the additional injuries, but generally the postprimary treatment is performed. Autografts and allografts, which can be also combined, are available for the reconstruction of the cruciate ligaments. The arthroscopic assisted operation starts with the drilling of all tibial and femoral tunnels using standard ACL and PCL arthroscopic instruments. The PCL is positioned after the graft has been transported into the joint through an anterolateral port, the ACL graft is positioned through the tibial drill hole and both are anchored first on the femoral and then on the tibial site i.e. with interference screws. In the postoperative rehabilitation neither immobilisation nor brace are used and progressive range of motion is allowed. The arthroscopic assisted reconstructions of the ACL and increasingly of the PCL are becoming standard procedures, but the technically difficult combined ACL/PCL reconstruction is restricted to a small number of arthroscopists. The first clinical results demonstrate, that the arthroscopic operation is comparable to the open reconstruction.

Anterior Cruciate Ligament↗

[Revision surgery in failed anterior cruciate ligament-plasty].

As the number of primary ACL reconstructions increases the frequency of revision ACL surgery will become more common. Revision surgery for the correction of recurrent functional instability requires a careful analysis to identify the potential causes of graft failure through a detailed history, physical examination and radiographic evaluation to ensure the success of the salvage procedure and to avoid repetition of errors. Technical considerations of revision ligament surgery like graft selection, hardware removal and new tunnel placement are presented.

Adult↗

Metallic versus bioabsorbable interference screw for fixation of bone-patellar tendon-bone autograft in arthroscopic anterior cruciate ligament reconstruction. A preliminary report.

We retrospectively compared the clinical outcome and the radiographic incorporation of the bone blocks between two groups of patients undergoing anterior cruciate ligament reconstruction using either metallic or bioabsorbable interference screws for fixation of the bone-patellar tendon-bone autograft. Sixty-nine patients (44 male and 25 female) were available for follow-up. There were 31 patients with a mean age of 33 years (range 16-59 years) in group I (bioabsorbable interference screw fixation) and 38 patients with a mean age of 32 years (range 18-58) in group II (metallic screw fixation). The mean follow-up was 9.6 months after surgery in group I (range 6-17 months) and 20.5 months in group II (range 6-32 months). At follow-up, the IKDC scores were comparable between the two groups, and there was no statistically significant difference for the Lysholm (P = 0.925) and Tegner (P = 0.197) scores. The KT-2000 tests showed a statistically insignificant mean side-to-side difference of 2.0 mm (+2.2 mm SD) in group I and 2.2 mm (+2.4 mm SD) in group II (P = 0.741). At follow-up, all patients showed osseous incorporation of the bone block autografts within the femoral and tibial bone tunnels with no osteolytic changes.

Adolescent↗

Knee evaluation in two systems and magnetic resonance imaging after operative treatment of posterior cruciate ligament injuries.

We reviewed 30 patients operated on because of acute (n = 14) or chronic (n = 16) rupture of the posterior cruciate ligament (PCL) with an average follow-up time of 6.9 years. The clinical outcome was expressed using the OAK and the International Knee Documentation Committee (IKDC) evaluation forms. All patients had undergone posterior stress X-radiography, 14 patients had additionally undergone magnetic resonance imaging (MRI). OAK score showed good or excellent results in 93% of the acute and 38% of the chronic cases. The IKDC form, however, revealed nearly normal results in only 29% of the acute and 6% of the chronic cases. The length and thickness of the operated PCL on MRI correlated with the clinical result.

Adolescent↗

[Holmium-YAG laser in outlet impingement of the shoulder. Mid-term results].

Arthroscopic widening of the subacromial space in the case of outlet impingement syndrome has many advantages over the open procedures. Arthroscopic subacromial decompression in case of impingement syndrome if refractory to conservative therapy, is an established procedure. The purpose of this study was to evaluate the results of arthroscopic subacromial decompression using the holmium:YAG laser and compare them with the result of the conventional arthroscopic procedure. In a prospective study, 47 patients with stage II and III impingement syndrome were divided into two groups. The first group (20 patients) underwent conventional arthroscopic subacromial decompression. The second group (27 patients) underwent arthroscopic subacromial decompression performed with the holmium:YAG laser. The results were assessed using the constant score preoperatively and postoperatively with a follow-up of at least 1 year for each patient. Improvement in the laser group was seen in the criteria of motion and pain. Abduction power, found to be improved after 1 week and 6 weeks in earlier investigation, showed no significant improvement at the follow-up time of 1 year. The average score of both groups increased after 1 year: in the laser group from 57.4 preoperatively to 75.3, in the conventional group from 49.7 to 65.7. There were no specific complications due to the laser application.

Adult↗

Correlation of MR imaging, CT arthrography, and arthroscopy of the shoulder.

Rotator cuff tears and instability of the glenohumeral joint are a common cause of chronic shoulder pain and disability. Currently CT arthrography is the method of choice to evaluate the extent of osseous and soft tissue abnormalities. This study was undertaken to determine if magnetic resonance imaging was able to depict post-dislocation abnormalities and rotator cuff pathology and if MRI can replace CT arthrography. Sixty four patients, who were operated on for the first time (arthroscopy or arthrotomy) between November 1986 and July 1991, were compared in a blinded fashion with the results of MR imaging in 40 cases and of CT arthrographies in 24 cases. For the evaluation of rotator cuff tears MRI proved to have a sensitivity of 83.3% and an accuracy of 90.3%. Labral pathology was depicted with a sensitivity of 69.2% and an accuracy of 87.1%. In cases involving a Hill-Sachs lesion the sensitivity of MRI was 90% and the accuracy 95%. MR imaging is an accurate method in the evaluation of rotator cuff pathology and to some extent labral abnormalities.

Adolescent↗

Locked posterior dislocation of the shoulder.

The posterior dislocation of the shoulder is a rare but clinically and radiologically well-defined entity. Missing its diagnosis can lead to locked dislocations, incorrect treatment, and shoulder dysfunction. The cases in this series will illustrate the typical errors of diagnosis and treatment, and the possible and recommended management strategies.

Adult↗

[Possibilities of shoulder arthroscopy in comparison with magnetic resonance tomography and arthro-computerized tomography].

In the last 15 years the methods of examination of the shoulder have intensively expounded. According to a well documented retrospective study we describe the value of the shoulder arthroscopy and its correlation to MRI and arthro-CT findings. MRI represents nowadays the best way of exploring rotator cuff lesions and of investigating an impingement syndrome. Associated with a contrast medium its ability to clear up an anterior or posterior shoulder instability is now superior to the arthro-CT's. The arthroscopy allows the dynamic exploration of the joint and can be used not only as a diagnostic but also as a therapeutic procedure.

Adolescent↗

Foreign-body reaction to the bioabsorbable suretac device.

SUMMARY: Arthroscopic shoulder stabilization with the bioabsorbable Suretac device (Acufex Microsurgical, Mansfield, MA) offers some technical advantages compared with other approaches. However, in 4 patients (3 men, 1 woman; between 20 and 35 years of age) with 3 SLAP lesions grades 2 and 1 post-traumatic anterior shoulder instability, breakage and early loosening of the Suretac device was observed. All patients complained about shoulder pain and loss of active and passive motion. The arthroscopic examination revealed a massive synovitis without positive cultures. Loose fragments of the Suretac device spread in the joint cavity and induced a foreign-body reaction. Histologically, there was a massive infiltration of phagocytic cells (histiocytes, multinucleated giant cells) and birefringent polymeric particles surrounded by or within histiocytes and multinucleated giant cells. All patients underwent arthroscopic synovectomy. Because of instability, 2 of them required restabilization, which was performed with suture anchors (Fastak [Arthrex, Naples, FL], Mitek [Mitek Division, Ethicon, Norderstedt, Germany]). Postoperatively all patients were pain free, progressing to full active and passive range of motion. Our patients suffered from a mechanical failure rather than from a predisposition to exaggerated inflammatory response. According to this observation, the Suretac device seems to be prone to early failure in patients with SLAP lesions because of its biodegradability.

Absorbable Implants↗

Tensile properties of the superior glenohumeral and coracohumeral ligaments.

Recent evidence has shown that the superior glenohumeral ligament (SGHL) and coracohumeral ligament (CHL) are important static stabilizers. To clarify the function of these two ligaments, we studied their tensile properties with bone-ligament-bone complexes from fresh-frozen shoulders, 10 SGHLs and 10 CHLs. Each ligament's cross-sectional area was measured, and uniaxial tensile testing of each complex was performed. The stiffness, ultimate load, percent elongation, and energy absorbed to failure of each bone-ligament-bone complex were derived from its load-elongation curve. The cross-sectional area of the coracohumeral ligament was significantly greater than that of the superior glenohumeral ligament of their midportions (CHL, 53.7 +/- 3.2 mm2 vs. SGHL, 11.3 +/- 1.6 mm2, p < 0.05). Results also reveal significant differences between the tensile properties for the two ligaments, with the coracohumeral ligament possessing greater stiffness (CHL, 36.7 +/- 5.9 N/mm vs. SGHL, 17.4 +/- 1.5 N/mm, p < 0.05) and ultimate load (CHL, 359.8 +/- 40.3 N vs. SGHL, 101.9 +/- 11.5 N, p < 0.05) than the superior glenohumeral ligament. Our findings confirm that the coracohumeral ligament is an important capsuloligamentous structure of the glenohumeral joint.

Adult↗

The spinoglenoid ligament and its relationship to the suprascapular nerve.

Entrapment of the suprascapular nerve by the inferior transverse scapular ligament or spinoglenoid ligament (SGL) has been discussed frequently in the literature, but it has not been well documented anatomically. Therefore the mechanism of entrapment is not well understood. When isolated atrophy and denervation of the infraspinatus muscle have been noted, compression of the muscle's motor branch at the spinoglenoid notch has been implicated. This anatomic and morphologic study investigates the role of the SGL in entrapment neuropathy of the infraspinatus. We used 23 shoulders from 19 cadavers, 5 women (8 shoulders) and 14 men (15 shoulders), with a mean age of 67.9 (54 to 78) years. The presence or absence of the SGL was noted. The length, width, and orientation of the SGL; size and shape of the tunnel to the infraspinatus fossa; and distance of the notch to the posterior glenoid rim were determined. The SGL was present in 14 (60.8%) shoulders, 5 (36%) women and 9 (64%) men. The SGL was wider at the superior entrance of the tunnel and fanned and twisted toward the inferior aspect. In all specimens the SGL fibers inserted into the posterior shoulder capsule. The mean length for the upper part of the SGL was 17.5 +/- 2.6 mm in men and 15.8 +/- 1.8 mm in women, and the lower part was 14.1 +/- 2.4 mm and 12.9 +/- 1.8 mm, respectively. The widths of the SGL at the origin of the scapular spine were 12.2 +/- 3.9 mm for men and 10.4 +/- 2.7 mm for women, whereas the insertion site widths were 15.8 +/- 2.2 mm for men, and 16.1 +/- 3.8 mm for women. The midportion width of the SGL was 6.8 +/- 1.9 mm in men and 5.8 +/- 2.1 mm in women. During cross-body adduction and internal rotation of the glenohumeral joint, the interaction of the SGL and the posterior capsule resulted in a tightening of the SGL. The suprascapular nerve moved laterally and stretched underneath the SGL in this position.

Aged↗

[Knee instability and varus malangulation - Simultaneous cruciate ligament reconstruction and osteotomy (Indication, planning and operative technique, results)].

AIM: Osteochondral lesions and osteoarthritis in young patients are often caused by chronic knee instability in varus malangulated knees. We present the indication, planning of the osteotomy as well as the operative technique and the results of our patients with simultaneous osteotomy and cruciate ligament reconstruction. MATERIALS/METHODS: From 4/96 until 12/00 58 patients ( 33 years) received simultaneous osteotomy (r = 57 correcting valgus, r = 1 varus malalignement) and cruciate ligament plasty (e = 49 ACL, n = 7 PCL, n = 2 ACL & PCL which routinely was performed in the arthroscopic technique after completion of the osteotomy (closed-wedge technique). Average correction angle of the osteotomy was 7 (4 - 10) degrees with a mean malalignement of 5 (0 - 10) degrees. 13 patients underwent additional cartilage surgery (osteochondral autograft transplantation, autologous chondrocyte transplantation, microfracturing), 2 patients received an implanted Collagen Meniscus (CMI) at the same time. RESULTS: Preoperatively the Lysholm score was 66 (35 - 81) points and increased to 81 (74 - 95), 87 (79 - 99) and 93 (88 - 99) points at 3, 6, and 12 months after surgery, respectively. Subjectively all patients reported an improvement of preoperative swelling, pain and instability. Additional cartilage surgery or meniscus implantation did not significantly alter the clinical score values. Complications were noted in 4 patients. CONCLUSIONS: Unstable varus malangulated knees can be sufficiently treated by osteotomy and cruciate ligament plasty at the same time, suggesting that unicompartimental decompression and treatment of instability is a causal and cost effective therapy delaying the progression of osteoarthritis and minimising clinical symptoms. Performing both operations in one procedure facilitates early rehabilitation and return of these patients to the activities of daily living and sports.

Adolescent↗

[Development of a 3-dimensional method to determine the tibial slope with multislice-CT].

AIM: The measurement or, respectively, the correction of the tibial slope is an important subject in the field of knee arthroplasty and in the procedure of cruciate ligament reconstruction. However, a valid value of the tibial slope cannot be obtained from the conventional plain X-rays in a reproducible way. The aim of this study was to evaluate the proximal tibial slope with a new CT measurement system and to compare the values with the X-ray method. METHOD: Using 6 cadaver tibiae, the antero-posterior slope of the proximal tibia was measured at 0 degrees, 2.5 degrees, 5 degrees, 10 degrees, 15 degrees, 20 degrees, 30 degrees internal rotation using the plain X-ray and spiral CT (3D-MPR reconstruction). Both methods were compared. RESULTS: The variation of the measurement of the tibial slope with the X-ray method was > 5 degrees even if the optimal 0 degrees rotation in the lateral view was applied. Moreover, the measurement error increased to 14 degrees while increasing the rotation of the tibia. Using the new CT system, the error was less than 3 degrees in all measurements. CONCLUSION: The measurement of the tibial slope in the conventional X-ray technique showed a high variation of the values depending on the rotation of the tibia in the lateral view. In contrast, the measurements with the new CT system represented a precise method with a small variation of the tibial slope values. For this reason detailed questions regarding the precise anatomy of the proximal tibia cannot be answered precisely with plain X-rays.

Anterior Cruciate Ligament↗

[Efficiency of a postoperative treatment after rotator cuff repair with a continuous passive motion device (CPM)].

AIM: The main objective of this study was to prove that a postoperative combined continuous passive motion (CPM) and physiotherapy treatment protocol (CPM group) can achieve 90 degrees active abduction in the shoulder joint earlier than physiotherapy alone (PT group). The indication was a complete tear of the rotator cuff. METHOD: The study was conducted under in-patient and out-patient conditions. 55 patients were included in this study. The prospective, randomized multicenter study design complies with DIN EN 540. The primary endpoint was the time span until 90 degrees active abduction was achieved by the patients. RESULTS: Patients in the CPM group reached the primary endpoint on average 12 days earlier than the control group. This difference was statistically significant (p = 0.0292). Analyzing the secondary endpoints, e. g., pain and disablement, the results in the CPM group showed again advantages of the combined treatment protocol (CPM + physiotherapy). CONCLUSION: The postoperative treatment of a total tear of the rotator cuff with a combined continuous passive motion and physiotherapy protocol provided a significantly earlier range of motion in the shoulder joint than physiotherapy alone. There was no report of CPM-related adverse effects.

Double-Blind Method↗