The influence of bicipital groove morphology on the stability of the long head of the biceps tendon.

PURPOSE: We aimed to evaluate the influence of the bony morphology of the bicipital groove on the stability of the long head of the biceps tendon (LHBT). METHODS: Among the patients who underwent magnetic resonance imaging of the shoulder at our outpatient clinic in 2012, those aged >40 years were included. After excluding cases with complete tear or unclear positioning of the biceps tendon, 464 shoulders were analyzed according to the position of the LHBT with respect to the bicipital groove. Shoulders with subluxation or dislocation of the LHBT were labeled as having unstable LHBT, while those with the LHBT located in the bicipital groove were labeled as having stable LHBT. The bony morphology of the bicipital groove was measured in terms of opening angle, medial wall angle, and depth. A shallow bicipital groove was defined as having an opening angle >94°, concurrent with earlier studies. We compared shoulders with stable and unstable LHBT regarding bicipital bony morphology. We also compared shoulders with normal and shallow grooves regarding tendon stability. RESULTS: Shoulders with stable and unstable LHBT differed significantly regarding bony morphology. Shoulders with unstable LHBT showed a shallower mean depth (by 0.3 mm; p = 0.008), a smaller mean medial angle (by 2.2°; p = 0.014), and a larger mean opening angle (by 3.7°; p = 0.016). Bony morphology characterized by a shallow groove was significantly associated with increased prevalence of instability defined as LHBT subluxation or dislocation ( p = 0.011). CONCLUSION: A shallow bicipital groove, identified by the larger opening angle, smaller medial angle, and shallower depth, may represent a predisposing factor for biceps tendon instability.

Individualised distal femoral cut improves femoral component placement and limb alignment during total knee replacement in knees with moderate and severe varus deformity.

AIM: Our aim was to determine the variation in valgus correction angle and the influence of individualised distal femoral cut on femoral component placement and limb alignment during total knee replacement (TKR) in knees with varus deformity. MATERIALS AND METHODS: The study was done prospectively in two stages. In the first stage, the valgus correction angle (VCA) was calculated in long-limb radiographs of 227 patients and correlated with pre-operative parameters of femoral bowing, neck-shaft angle and hip-knee-ankle angle. In the second part comprising of 240 knees with varus deformity, 140 (group 1) had the distal femoral cut individualised according to the calculated VCA, while the remaining 100 knees (group 1) were operated with a fixed distal femoral cut of 5°. The outcome of surgery was studied by grouping the knees as varus <10°, 10-15° and >15°. RESULTS: Of the 227 limbs analysed in stage I, 70 knees (31 %) had a VCA angle outside 5-7°. Coronal bowing (p < 0.001), neck-shaft angle (p < 0.001) and preoperative deformity (p < 0.001) significantly influenced VCA. Results of the second phase of the study showed a significant improvement in both femoral component placement and postoperative alignment when VCA was individualised in the groups of knees with varus 10-15° (p 0.002) and varus >15° (p 0.002). CONCLUSION: Valgus correction angle is highly variable and is influenced by femoral bowing, neck-shaft angle and pre-operative deformity. Individualisation of VCA is preferable in patients with moderate and severe varus deformity. LEVEL OF EVIDENCE: Level 2.

Determinants of Femoral Tunnel Length in Anterior Cruciate Ligament Reconstruction: CT Analysis of the Influence of Tunnel Orientation on the Length.

PURPOSE: The purpose of the study was to identify the femoral tunnel orientation that consistently results in a tunnel length of more than 35 mm in anterior cruciate ligament reconstruction. MATERIALS AND METHODS: Computed tomography (CT) scans were obtained from 30 patients who did not have any pathology in the distal femur. Virtual tunnels were marked on 3D (3-dimensional) reconstructed CT images after determining the orientation defined by sagittal inclination and axial angle. The length of a femoral tunnel in 64 different combinations of orientations (between 30° and 65° in 5° increments in two planes) was measured on 3D reconstructed images in both knees in 30 patients. Reliability of measurement was assessed with correlation coefficient for intra-observer and inter-observer measurements. A one-way analysis of variance (ANOVA) was used for statistical analysis. RESULTS: The mean femoral tunnel length varied significantly with each 10° change in orientation in both planes (p<0.05, ANOVA). A femoral tunnel of more than 35 mm in length could be obtained only with a sagittal inclination of more than 50° and axial angle of 30°-45°. When the axial angle was kept constant, the tunnel length increased with the increase in sagittal inclination. Higher sagittal inclinations consistently resulted in longer tunnels (r>0.9) and reduced the incidence of posterior cortical breakage. CONCLUSIONS: A tunnel orientation with an axial angle between 30°-45° and a sagittal inclination of more than 50° can result in a tunnel length of more than 35 mm.