Klaus Schlüter-Brust

Mid-range outcomes in 64 consecutive cases of multilevel fusion for degenerative diseases of the lumbar spine

In the treatment of multilevel degenerative disorders of the lumbar spine, spondylodesis plays a controversial role. Most patients can be treated conservatively with success. Multilevel lumbar fusion with instrumentation is associated with severe complications like failed back surgery syndrome, implant failure, and adjacent segment disease (ASD). This retrospective study examines the records of 70 elderly patients with degenerative changes or instability of the lumbar spine treated between 2002 and 2007 with spondylodesis of more than two segments. Sixty-four patients were included; 5 patients had died and one patient was lost to follow-up. We evaluated complications, clinical/radiological outcomes, and success of fusion. Flexion-extension and standing X-rays in two planes, MRI, and/or CT scans were obtained pre-operatively. Patients were assessed clinically using the Oswestry disability index (ODI) and a Visual Analogue Scale (VAS). Surgery performed was dorsolateral fusion (46.9%) or dorsal fusion with anterior lumbar interbody fusion (ALIF; 53.1%). Additional decompression was carried out in 37.5% of patients. Mean follow-up was 29.4±5.4 months. Average patient age was 64.7±4.3 years. Clinical outcomes were not satisfactory for all patients. VAS scores improved from 8.6±1.3 to 5.6±3.0 pre- to post-operatively, without statistical significance. ODI was also not significantly improved (56.1±22.3 pre- and 45.1±26.4 post-operatively). Successful fusion, defined as adequate bone mass with trabeculation at the facets and transverse processes or in the intervertebral segments, did not correlate with good clinical outcomes. Thirty-five of 64 patients (54%) showed signs of pedicle screw loosening, especially of the screws at S1. However, only 7 of these 35 (20%) complained of corresponding back pain. Revision surgery was required in 24 of 64 patients (38%). Of these, indications were adjacent segment disease (16 cases), pedicle screw loosening (7 cases), and infection (one case). At follow-up of 29.4 months, patients with radiographic ASD had worse ODI scores than patients without (54.7 vs. 36.6; P<0.001). Multilevel fusion for degenerative disease still has a high rate of complications, up to 50%. The problem of adjacent segment disease after fusion surgery has not yet been solved. This study underscores the need for strict indication guidelines to perform lumbar spine fusion of more than two levels.

Relationship between human femorotibial joint configuration and the morphometry of the anterior cruciate ligament.

IntroductionIndividual variations in the anatomy of the knee joint have been suggested to affect the ability to functionally compensate for ACL insufficiency or to put an individual at an increased risk of ACL injury. These variations include the posterior tibial slope, the concavity of the medial tibial plateau, the convexity of the lateral tibial plateau, and the configuration of the femoral condyles.MethodThis anatomical study investigates if there is a correlation between the individual surface geometry of the femorotibial joint and the morphometry of the ACL. These data were assumed to provide evidence whether or not the functional stability of an ACL-insufficient knee may be derived from its radiographic surface geometry. Standardised measurement techniques were used to analyse the surface geometry of 68 human cadaver knees. Data were correlated with the cross-sectional area, the area of insertion and position of the footprint of the ACL and its functional bundles.ResultsAnalysis revealed that there was a significant, but weak correlation between the femoral and tibial area of ACL insertion and the depth of the medial and lateral femoral condyle. No correlation was found between the surface geometry of the femorotibial joint and the cross-sectional area of the ACL. The results of this anatomical study suggest that the relationship between the joint surfaces and the morphometry of the ACL primarily is a function of size of the knee joint.ConclusionsBased on our results, there is no evidence that the stability of the knee can be derived from its radiographic surface geometry.