Radiographs of 20 plastinated human cadaveric lower legs were obtained in 12 positions of rotation to determine the optimal parameter for reliable assessment of syndesmotic and ankle integrity, and to assess the effect of positioning of the ankle on this parameter. Three observers measured eight parameters twice after four repetitions of ankle positioning. Intraclass correlation coefficients and reproducibility were assessed. Some tibiofibular overlap was present in all radiographs in any position of rotation. The medial clear space was smaller than or equal to the superior clear space in all radiographs. Intraclass correlation coefficients of the other parameters were too weak for reliable quantitative measurements, as was shown with a mixed model analysis of variance. This resulted from the inability to reproduce ankle positioning, even under optimal laboratory circumstances. This study shows that no optimal radiographic parameter exists to assess syndesmotic integrity. Tibiofibular overlap and medial and superior clear space are the most useful, because one-sided traumatic absence of tibiofibular overlap may be an indication of syndesmotic injury, and a medial clear space larger than a superior clear space is indicative of deltoid injury. Additional quantitative measurement of all syndesmotic parameters with repeated radiographs of the ankle cannot be done reliably and therefore are of little value.

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PurposeIn total knee arthroplasty, tissue-sparing techniques are considered more important, as functional gain could become more advantageous when early mobilization is commenced. The parapatellar approach is most often used, whereas the subvastus approach is a suitable alternative. Presently, it is unknown, according to true objective measurements, which of the two is most advantageous.MethodsIn this prospective randomized double-blind, short-term trial measurements (KSS, WOMAC, PDI, VAS, ability to perform) were obtained at day 1, day 3, 1 week, 6 weeks, and 3 months.ResultsThe subvastus group (n = 20) showed only significantly less extension lag direct postoperative (P = 0.04) compared with the parapatellar group (n = 20). Other scores were not significantly different. The Dynaport®knee test, an objective performance-based tool, could not demonstrate significant differences. A blunt anatomical dissection was carried out in both observational and histological to support findings. A dense innervation of the distal vastus medialis was found. This is at risk employing the subvastus approach. Both approaches harm the suprapatellar bursa. The vastus medialis sheath must be detached distally to open the knee joint. No true separate vastus medialis obliquus could be identified.ConclusionComparable to literature, only mild advantage employing the subvastus approach was found, but only early postoperative and not objectively. As this approach is also not suitable in every case, we will continue to use the parapatellar approach.

The purpose of this ex vivo biomechanical study was to determine the strength and stiffness of the anterior and posterior syndesmotic tibiofibular ligaments and the posterior tibiotalar component of the deltoid ligament. Injuries to these ligaments are a prevalent clinical problem, yet little is known about their mechanical behavior. Ten fresh-frozen cadaver lower extremities (average age at death, 72 +/- 8 years) were harvested. The anterior and posterior tibiofibular ligaments and the posterior tibiotalar component of the deltoid were isolated and prepared as bone-ligament-bone complexes for tensile testing to determine strength, stiffness, and mode of failure. The posterior tibiofibular ligament exhibited greater strength, but not significantly so (p < .05), than the anterior tibiofibular ligament and the posterior tibiotalar component of the deltoid ligament. There were no significant differences in stiffness between the three ligaments tested. The dominant mode of failure for the anterior tibiofibular ligament was ligament substance rupture, primarily near its fibular insertion, whereas the failure modes of the posterior tibiofibular ligament were evenly split between substance ruptures and fibular avulsions. The posterior tibiotalar component of the deltoid ligament ruptured most often near the talar insertion. The tibiofibular ligaments showed greater strength than the lateral collateral and deltoid ligaments, as mentioned in literature. The greater strength of the tibiofibular ligaments relative to the lateral collateral and deltoid ligaments suggests that these ligaments play an important role in ankle constraint.

Displacement transducers were placed across the anterior and posterior tibiofibular ligaments of 17 fresh cadaver (78.4 +/- 6.7 years old at death) lower extremities. Displacements induced by various clinical tests (squeeze, fibula translation, Cotton, external rotation, and anterior drawer) were measured with the ankle ligaments intact and after sequential sectioning of the anterior tibiofibular ligament, anterior deltoid ligament, and posterior tibiofibular ligament. None of the syndesmotic stress tests could distinguish which ligaments were sectioned. Furthermore, the small displacements measured during the stress tests (with the exception of the external rotation test) suggest it is unlikely that the displacement induced in injured syndesmoses can be clinically differentiated from normal syndesmoses. Therefore, pain, rather than increased displacement, should be considered the outcome measure of these tests.

The Dynaport Knee Test showed a significant functional advantage for patients with a resurfaced patella [44 vs. 39.7 (P = 0.042)], whereas KSS and The Minimod were not significant (P values ranging from 0.07 to 0.75). Similar to other reports in literature, using the KSS, it was not possible to identify significant difference between patella resurfacing or retaining in total knee arthroplasty, however using a performance based test it was possible to determine significant difference. The found advantage of patella resurfacing may be less due to pain relief but due to a functional benefit during demanding motion tasks. This finding indicates that current measurement tools may not be accurate or specific enough to detect this difference. Therefore, we recommend complementing the classic evaluation tools with an objective functional test, when conducting a randomized trial to answer the indecision whether to resurface the patella or not.

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