To wedge or not to wedge; A cadaveric comparison study of two medial malleolar osteotomy modalities.

OBJECTIVE: To quantify the surface area of the talus accessible with a uniplanar and a biplanar medial malleolus osteotomy. Our secondary purpose study is to quantify the amount of weightbearing area that each osteotomy effects on the tibial articular surface. PATIENTS AND METHODS: Eight ankle joint specimens were dissected for this study. The uniplanar osteotomy was performed first. A K-wire marked the limits of access at two different angles: 90° and 30°. The boundaries were marked with a skin marker. Wedges were then created on the tibia plafond, and the osteotomy was converted into a biplanar one. Measurements were repeated again for this osteotomy. The talus, the tibial plafond, and the medial malleolus were then excised. Images were taken and then electronically calibrated for two-dimensional digital measurement of accessible areas. Areas of perpendicular and 30-degree access were recorded for both osteotomies. The articular surface of the tibia was also measured, and an area analysis was performed to calculate the amount of weightbearing cartilage removed by each osteotomy. RESULTS: Almost the entire sagittal plane was accessible with both osteotomies. At a 30° angle, bone purchase was achieved for 67.7 % of the talar articular surface with the uniplanar osteotomy and for 74.8 % with the biplanar osteotomy. At a 90° angle, uniplanar osteotomy provided access to 32.7 % of the talar articular area, whereas the biplanar osteotomy achieved an average coverage of 52.8 %. The difference was statistically significant. On average, 25.3 % of the weightbearing area of the tibial plafond is affected when a biplanar osteotomy is performed. CONCLUSION: Medial malleolar osteotomy provides varying degrees of access to the talar dome depending on how it is performed. A wedge-shaped biplanar osteotomy provides greater access and is therefore more suitable for defects located deeper on the talar dome. Despite providing wider access, it results in greater disruption of the weightbearing cartilage of the tibial plafond. LEVEL OF EVIDENCE: Level V.

Association of Medial Meniscus Extrusion With the Prominence of a Fascicular Capsulofemoral Band Subjacent to the Deep Medial Collateral Ligament.

OBJECTIVE: The objective of our study was to test our hypothesis that a transverse oblique fascicular anteromedial capsulofemoral band partially subjacent to the deep medial collateral ligament (MCL) is more prominent in knees with medial meniscal extrusion. MATERIALS AND METHODS: We retrospectively analyzed all knee MRI examinations from a 6-month period for the presence and dimensions of the anteromedial capsulofemoral band on coronal proton-density fat-saturated images and also for medial meniscus extrusion, which was defined as extrusion of 3 mm or greater. Edemalike signal intensity within or in the vicinity of the anteromedial capsulofemoral band, partial or complete tears of the MCL, a history of MCL surgery, or a neoplastic mass lesion violating the medial supporting structures were exclusion criteria. We reviewed procedural videos of patients who subsequently underwent knee arthroscopy. MRI of a cadaveric knee was performed and was followed by dissection and histologic examination. RESULTS: MRI examinations of 346 knees of 312 patients met the inclusion criteria; of these knees, 50 had medial meniscus extrusion. The anteromedial capsulofemoral band was discernible on MRI in all knees except five (98.6%), and it was visible in six of the arthroscopy videos of 17 knees. The anteromedial capsulofemoral band was thicker on MRI of patients with medial meniscus extrusion (p < 0.0001). The anteromedial capsulofemoral band was identified on MRI and at dissection of the cadaveric knee, and histologic examination revealed that the anteromedial capsulofemoral band was a capsuloligamentous structure. CONCLUSION: A transverse oblique anteromedial capsulofemoral band subjacent to the deep MCL is thicker in knees with medial meniscus extrusion.

Redefining the proximal ulna anatomy.

PURPOSE: Complex fractures of the olecranon have always been a difficult condition for treatment. Successful reconstruction depends on restoration of the anatomic contributors to stability. The purpose of this study was to define the proximal ulna anatomy in detail with respect to fracture fixation and arthroscopy. METHODS: In 50 normal adult ulnae (26 left, 24 right); posterior olecranon height (POH), olecranon width (OW), trochlear notch width (TW), the distances between the olecranon and the trochlear notch on radial and ulnar sides (RTH, UTH), and proximal ulnar angulations were measured with a ruler and a digital goniometer. RESULTS: The average POH was 24.6 mm, OW was 23.1 mm, TW was 22.3 mm, RTH was 16.2 mm, and UTH was 15.8 mm. The mean value for proximal ulna torsion angle (PUTA) was found 11.1°. The mean varus angulation was 9.3°. The average articular angle was 27.7° and proximal ulnar dorsal angulation (PUDA) was 8°. CONCLUSIONS: The unique bony architecture of the proximal ulna presents particular difficulties for the implants used in fracture fixation and arthroplasty of the elbow. Knowing the detailed anatomy of the variations of proximal ulna will guide the surgeon to obtain a more reliable length of the olecranon and to offer a safe place for Kirschner wire replacement concerning humero-ulnar joint functionality. In this study, PUTA was also defined. The angle determines the rotation of the proximal ulna and it has a great importance for the movements of the joint. The measured angulations will help the surgeon to design the proper prosthesis for the maintenance of the functions of the elbow joint.