The risk of graft impingement still exists in modern ACL surgery and correlates with degenerative MRI signal changes.

PURPOSE: Anatomic tunnel placement in ACL reconstruction is crucial to restore knee function. The aims of this study were to (i) evaluate the accuracy of tunnel placement for primary state-of-the-art ACL reconstruction, and (ii) examine the correlation between incorrect tunnel placement, graft appearance, and notch impingement. METHODS: In this retrospective study, all patients underwent primary single-bundle ACL reconstruction with independent drilling of the femoral and tibial tunnels according to anatomical landmarks. The accuracy of tunnel placement and the rate of notch impingement were analysed with MRI. The study cohort was subdivided according to the morphology of the graft: intact, degeneration, and re-rupture. The objective outcome was evaluated with the IKDC objective score, and the subjective outcomes were evaluated with the IKDC subjective score, the Lysholm knee score, the KOOS, and the Tegner activity scale score. RESULTS: Eighty-seven consecutive patients with a mean follow-up of 3.8 ± 1.4 years were evaluated. There was no significant difference among the groups concerning the baseline characteristics. The re-rupture rate was 9.2%. The position of the femoral tunnel was correct in 92% of the patients, and the position of the tibial tunnel was correct in 93% of the patients. In the intact group, impingement was not found in any of the cases, whereas the rate of impingement in the degeneration (65%) and re-rupture (80%) groups was significantly higher than that in the intact group (p < 0.001). The risk of impingement was more likely with femoral (71% vs. 13%, p < 0.001) or tibial (100% vs. 11%, p < 0.001) malpositioning. The objective IKDC score was A in 52 patients (60%), B in 26 patients (30%), and C in 9 patients (10%). The average subjective IKDC score, Lysholm score, and KOOS were comparable in the intact and degeneration groups but significantly lower in the patient group with newly diagnosed re-ruptures (p = 0.05). The Tegner activity scale score was comparable in all three groups. CONCLUSION: Even though the accuracy of femoral tunnel placement in modern single-bundle ACL reconstruction is greater, the risk of malpositioning and graft impingement remains. In our patient cohort, there was a clear correlation between ACL graft impingement, degenerative changes in MRI, and incorrect tunnel positioning. The surgeon must focus on accurate tunnel placement specific to individual patient anatomy. LEVEL OF EVIDENCE: Level III.

ACL reconstruction with femoral and tibial adjustable versus fixed-loop suspensory fixation: a retrospective cohort study.

BACKGROUND: Cortical suspensory fixation (CSF) devices gain more and more popularity as a reliable alternative to interference screws for graft fixation in anterior cruciate ligament (ACL) reconstruction. Adjustable-loop fixation may be associated with increased anterior laxity and inferior clinical outcome. The purpose of the study was to compare anterior laxity and clinical outcome after minimally invasive all-inside ACL reconstruction using an adjustable-loop (AL) to a standard technique with a fixed-loop (FL) CSF device. METHODS: Patients who underwent primary single-bundle ACL reconstruction with a quadrupled hamstring autograft at a single institution between 2012 and 2016 were reviewed. In the AL group minimally invasive popliteal tendon harvesting was performed with an all-inside approach (femoral and tibial sockets). In the FL group a traditional anteromedial approach was used for tendon harvesting and a femoral socket and full tibial tunnel were drilled. An objective clinical assessment was performed with Telos x-rays and the International Knee Documentation Committee (IKDC) Objective Score. Patient-reported outcomes (PRO) included the IKDC Subjective Score, the Lysholm Knee Score, the Knee Injury and Osteoarthritis Score (KOOS) and the Tegner Activity Scale. RESULTS: A total of 67 patients were enrolled in this retrospective study with a mean follow-up of 4 (± 1.5) years. The groups were homogenous at baseline regarding age, gender, and the time to surgery. At follow-up, no statistically significant differences were found regarding anterior laxity (AL: 2.3 ± 3 mm vs. FL: 2.3 ± 2.6 mm, p = 0.981). PRO scores were comparable between the AL and FL groups (IKDC score, 84.8 vs. 88.8, p = 0.185; Lysholm 87.3 vs. 89.9, p = 0.380; KOOS 90.7 vs. 91.4, p = 0.720; Tegner 5.5 vs. 6.2, p = 0.085). The rate of saphenous nerve lesions was significantly lower in the AL group with popliteal harvesting of the tendon (8.3% vs. 35.5%, p = 0.014). CONCLUSION: The use of an adjustable-loop device on the femoral and tibial side led to similar stability and clinical results compared to a fixed-loop device.

[Experimental and clinical examinations of the effect of cryosurgery of intraocular pressure]. / Experimentelle und klinische Untersuchungen zer kryochirurgischen Beeinflussung des intraokularen Druckes.

Diathermy and cryosurgery have different effects on living tissue. Cell membranes are ruptured by cryosurgery, but the proteins are less affected than by diathermy. A short review of experimental cyclocryosurgery and the clinical results are presented. Data from the literature as well as evaluation of patients confirm that, as yet, the results are not satisfactory. The sequelae of freezing are very different in slow-and fast-freezing procedures. Therefore, the results in rabbits treated with a cryosurgical unit used for retinal detachment surgery (Amoils, -80 degrees C) were compared with the results using a cryoprobe cooled with liquid nitrogen (-180 degrees C). A permanent reduction in intraocular pressure was not achieved using cyclocryotherapy applied with the equipment used for detachment surgery (-80 degrees C). Repeated cryosurgery of this type did not result in a permanent pressure reduction. Histopathology demonstrated that the ciliary epithelium had regenerated and prolongation of the cyclocryotherapy applications did not result in a permanent intraocular pressure reduction. Lens opacities occurred in all rabbits of this series. Application of cryotherapy with a nitrogen-cooled cryoprobe (2.5 mm2 contact area) caused severe damage, resulting in phthisis bulbi. Another nitrogen-cooled probe (contact area of about 1 mm2 diameter) resulted in a permanent reduction in intraocular pressure, but the anterior parts of the lens became opaque. Histopathology revealed total necrosis of the ciliary epithelium and the basal membrane. Three months after cyclocryotherapy of this type the ciliary processes were atrophic and covered with connective tissue and regeneration of epithelial cells was not found in areas of such cryotherapy scars. Further experiments have been commenced including a reduction of application time, in order to find the optimum application technique resulting in permanent intraocular pressure reduction and the fewest possible side effects.

Nadolol and labetalol: comparative efficacy of two beta-blocking agents in glaucoma.

The beta-blocking agent Nadolol and the beta- and alpha-blocking agent Labetalol were screened for their potential efficacy on intraocular pressure (IOP) in glaucoma. Nadolol 2% and Labetalol 1% in aqueous solution were investigated in a single-dose manner on the basis of a double-masked clinical trial. Only Nadolol reduced IOP significantly which was maximal 4 h after drug application and had a duration of action of at least 6 h and less than 24 h. Blood pressure, pulse rate, and pupil diameter were not significantly affected, and Labetalol did not change either parameter significantly. It is concluded that Nadolol may be of use in glaucoma therapy.

[Computer perimetry of glaucomatous visual field defects at different stimulus sizes (author's transl)]. / Die computerperimetrische Darstellung glaukomatöser Gesichtsfelddefekte in Abhängigkeit von der Stimulusgrösse.

The influence of stimulus size in computer perimetry of central visual field defects was investigated in 30 glaucomatous eyes of 30 patients. 12 eyes had been studied utilizing stimulus size 1 and 3, 18 eyes with stimulus size 3 and 5 at the computer perimeter Octopus (program 31). Using large test targets small scotomata can be overlooked and identified field defects appear smaller and less deep. To evaluate this well-known phenomenon quantitatively by computerized perimetry was the aim of the present study. The mean threshold values in the diseased areas of the glaucomatous fields were about 6--10 db higher with stimulus size 3 than 1 and again 6--10 dB higher with stimulus 5 in comparison to 3. The clinical significance of these findings is discussed for different types of perimetry.