Cartilage degeneration of patellofemoral joint occurs in open wedge high tibial osteotomy, rather than in hybrid closed wedge high tibial osteotomy, during the early postoperative period: A qualitative analysis using MRI T2 mapping.

PURPOSE: After high tibial osteotomy, the patella may change position and osteoarthritis of the patellofemoral joint (PFJ) may occur. It was hypothesized that the course of PFJ degeneration would differ between open wedge high tibial osteotomy (OWHTO) and hybrid closed wedge high tibial osteotomy (hybrid HTO). Accordingly, this study aimed to evaluate the qualitative changes in PFJ articular cartilage, during the early postoperative period after OWHTO and hybrid HTO. METHODS: This was a retrospective observational study of 75 knees that underwent OWHTO (N = 37) or hybrid HTO (N = 38) for medial knee osteoarthritis. OWHTO and hybrid HTO were indicated for corrections of less than 10° and more than 10°, respectively. MRI of all knees was performed before and 6 months after surgery to evaluate patellar cartilage in sagittal images for T2 mapping. Three regions of interest (medial, middle, and lateral facets) were defined in the articular cartilage, and T2 values were measured. Patellar tilting angle, lateral shift ratio, and patellar height were compared before and after surgery. RESULTS: There was no significant change in arthroscopic findings of PFJ articular cartilage between the OWHTO and hybrid HTO groups. In the OWHTO group, the mean T2 value of medial and middle facets increased significantly (lateral, 43.0 ± 3.9 to 43.7 ± 3.5; middle, 44.2 ± 3.9 to 46.2 ± 3.8; medial 41.0 ± 4.3 to 42.4 ± 4.0). Conversely, no significant change was observed in the hybrid HTO group (lateral, 41.1 ± 4.0 to 42.3 ± 4.0; middle, 43.6 ± 4.2 to 44.5 ± 4.3; medial, 40.7 ± 4.1 to 41.5 ± 4.5). Patellar height decreased and increased in the OWHTO and hybrid HTO groups, respectively, and patellar tilt decreased in the OWHTO group. Lateral shift ratio decreased significantly in both groups. CONCLUSIONS: OWHTO with a small correction angle may result in qualitative changes in PFJ articular cartilage from an early stage, while hybrid HTO with a relatively large correction angle is unlikely to affect PFJ articular cartilage.

Revision Anterior Cruciate Ligament Reconstruction Using Semitendinosus Tendon With Bone Fragment.

After anterior cruciate ligament (ACL) reconstruction, the tibial tunnel becomes widened over time. A revision surgery of the ACL reconstruction is required to fill the widened tunnels. Bone-patellar tendon-bone grafts often are used to fill enlarged bone tunnels. However, due to the variation in tendon length, it is often difficult to adjust the position of the bone fragment to the enlarged part of the bone tunnel. This study describes an arthroscopic ACL reconstruction technique using the semitendinosus tendon as well as a bone fragment which is placed in the enlarged tibial tunnel. The tendon and cortical bone were collected together at the tendon attachment using a flat chisel. The bone fragment was inserted through the tendon in a controlled manner and ultimately placed at the posterior wall of the tibial foramen. This technique was determined to be less invasive than using bone-patellar tendon-bone in a 2-stage revision ACL reconstruction. In addition, this technique can be easily performed by any surgeon who is accustomed to conventional ACL reconstruction using the semitendinosus tendon and does not require any special equipment. Our findings suggest that this technique may be useful for revision ACL reconstruction.

Arthroscopic Fixation Technique for Avulsion Fracture of the Posterior Cruciate Ligament From the Tibia.

This study describes an arthroscopic pullout fixation technique for small and comminuted avulsion fractures of the posterior cruciate ligament from the tibia. Intra-articular surgery required 3 arthroscopic portals, the anterolateral, anteromedial, and posteromedial portals. To simplify surgery, the posterolateral portal was omitted. A 2.4-mm K-wire was inserted through the anterior incision to the center of the bone fragment. This central guidewire was subsequently overdrilled with a 4.0-mm cannulated drill. The fixation material consisted of Pass Telos artificial ligaments inserted through the fiber loop of a fixed suspensory device such as RIGIDLOOP. The leading end of the thread of the RIGIDLOOP was pulled out through the anteromedial portal. The button of RIGIDLOOP was gradually advanced through the bone tunnel. The button was pulled out and flipped over the bony fragment. The artificial ligament was pulled distally to reduce the bony fragment, and fixed onto the tibia using a ligament button while applying anterior drawer force to the proximal tibia with the knee flexed at 90°. This minimally invasive procedure was successful in treating small and comminuted avulsion fracture of the tibial attachment of the posterior cruciate ligament.

Length change patterns and shape of a grafted tendon after anatomical medial patellofemoral ligament reconstruction differs from that in a healthy knee.

PURPOSE: Recurrent patellar dislocation is currently treated with anatomical reconstruction of the medial patellofemoral ligament (MPFL), and favourable postoperative outcomes have been reported. However, it is uncertain if healthy MPFL function is restored by anatomical reconstruction. The hypothesis in this study was that stabilization of the patella following MPFL reconstruction would be improved compared with that before surgery, but that function of the grafted tendon would differ from that of a healthy MPFL. The objective was to analyse the length change patterns of the MPFL before surgery and the grafted tendon after surgery in patients with recurrent patellar dislocation treated with anatomical MPFL reconstruction. METHODS: The subjects were 12 patients (13 knees) in whom recurrent patellar dislocation was treated with anatomical MPFL reconstruction. The length change patterns of the MPFL and reconstructed ligament were analysed at extension and flexion of the knee joint using open MRI. RESULTS: The postoperative grafted tendon length was significantly shorter than that of the preoperative MPFL at knee extension, and significantly longer at 90° and 120° of knee flexion. The postoperative length of the grafted tendon only changed slightly from 0° to 30° of knee flexion, and then significantly decreased at flexion of 30° or more. The morphology of the grafted tendon was linear until 60° knee flexion, but became convex toward the extraarticular side at flexion of 90° or more. CONCLUSION: The grafted tendon length at knee extension was shorter than that of the preoperative MPFL, but there was no significant difference at 30° flexion. These findings suggest that the effect of damping of the patella with a grafted tendon after MPFL reconstruction may differ from that in a healthy knee. In addition, the morphology at 60° knee flexion was improved to linear after surgery, suggesting that ligament morphology at this flexion was normalized by MPFL reconstruction. LEVEL OF EVIDENCE: III.

Fixed-flexion view X-ray of the knee superior in detection and follow-up of knee osteoarthritis.

A fixed flexion view (FFV) is useful for evaluating joint space when assessing the severity of osteoarthritis (OA) of the knee. We analyzed changes in joint space revealed by standing extended view (SEV) and FFV over a mean 4 years, to compare both views on their capacity to measure joint space width accurately at particular time points during follow-up.SEV and FFV images were acquired in patients with knee OA. The 81 patients (157 knees) followed up for ≥24 months were selected as study subjects. Medial joint space widths (MJSW), Kellgren-Lawrence (KL) grades, and reductions in MJSW on SEV (ΔSEV) and FFV (ΔFFV) were compared in knees evaluated by SEV and FFV.At both time-points, mean MJSW was significantly lower by FFV than by SEV. Mean MJSW was significantly lower at follow-up than at first examination by both SEV and FFV. At both time-points, the KL grade was higher by FFV than by SEV group. The ΔFFV was significantly greater than the ΔSEV. ΔSEV did not differ significantly among KL grades, but ΔFFV was significantly greater in patients with KL grade II than in patients with other KL grades.FFV is not only useful for evaluating joint space in knees with OA, but also for accurately evaluating the progression of OA. The risk of rapid progression of knee OA may be higher in patients with KL grade II, as determined by FFV. FFV may be superior to SEV in determining appropriate treatment strategies for knee OA.

Radiographic Measurement of Joint Space Width Using the Fixed Flexion View in 1,102 Knees of Japanese Patients with Osteoarthritis in Comparison with the Standing Extended View.

PURPOSE: The fixed flexion view (FFV) of the knee is considered useful for evaluating the joint space when assessing the severity of osteoarthritis (OA) of the knee. To clarify the usefulness of FFV for evaluation of the joint space and severity of knee OA, this study evaluated changes in the joint space on the FFV and standing extended view (SEV) in patients with knee OA. MATERIALS AND METHODS: The SEV and FFV images were acquired in 567 patients (1,102 knees) who visited the hospital with a chief complaint of knee joint pain. Medial joint space width (MJSW) and Kellgren-Lawrence (K-L) classification assessed using the SEV and FFV images were compared. RESULTS: Mean MJSW was significantly smaller when assessed on the FFV than on the SEV (3.02±1.55 mm vs. 4.31±1.30 mm; p<0.001). The K-L grade was the same or higher on the FFV than on the SEV. CONCLUSIONS: The FFV is more useful than the SEV for evaluating the joint space in OA knees. Treatment strategies in patients with knee OA should be determined based on routinely acquired FFV images.