Toshikazu Kubo

Comparative Effects of Periarticular Multimodal Drug Injection and Single-Shot Femoral Nerve Block on Pain Following Total Knee Arthroplasty and Factors Influencing Their Effectiveness

Purpose This study compared the analgesic effects of local infiltration analgesia (LIA) and femoral nerve block (FNB) after total knee arthroplasty (TKA) and assessed factors associated with analgesia obtained by these two methods. Materials and Methods Study subjects included 66 patients (72 knees) who underwent TKA for osteoarthritis of the knee. Pain visual analogue scale (VAS), the amount of analgesics used, number of days to achieve 90° of flexion of the knee joint, date of initiating parallel-bar walking, range of motion of the knee joint at discharge, and adverse events were investigated. Results The VAS scores did not differ significantly between two groups, whereas the amount of analgesics used was significantly lower in the LIA group. Preoperative flexion contracture was significantly more severe in the LIA group with high VAS compared with low VAS. No serious adverse event occurred in the LIA or FNB group. Conclusions The lower analgesic usage in the LIA group than the FNB group indicates that the analgesic effect of LIA was greater than that of singleshot FNB after TKA. There were no serious complications in either group. The postoperative analgesic effect of LIA was smaller in patients with severe than less severe preoperative flexion contracture.

Factors affecting range of motion after total knee arthroplasty in patients with more than 120 degrees of preoperative flexion angle.

PurposeThe postoperative flexion angle reportedly shows a positive correlation with the preoperative flexion angle, but in some cases, the postoperative flexion angle decreases in patients with a large preoperative flexion angle. The purpose of this study was to investigate factors affecting the range of motion after total knee arthroplasty (TKA) in patients with a large preoperative flexion angle.MethodsThe study evaluated 120 knees with more than 120 degrees of preoperative flexion angle that underwent NexGen LPS-Flex mobile bearing. The groups with and without a reduction in the postoperative flexion angle were compared. Also, a logistic regression analysis was performed, where the presence or absence of a reduction in the postoperative flexion angle was the dependent variable and age, sex, body mass index (BMI), preoperative femorotibial angle (FTA), γ angle, δ angle, pre/postoperative change amount in posterior condylar offset (PCO), pre/postoperative change amount in joint line, and pre/postoperative change amount in patellar thickness were independent variables.ResultsThose with preoperative FTA of 186° or larger did not have a reduction in the postoperative flexion angle, compared with the angle of 185° or smaller. Those with δ angle of 83° or smaller also did not have a reduction in the postoperative flexion angle, compared with the angle of 84° or larger.ConclusionsOur results showed that preoperative FTA and δ angle had an impact on a reduction in the postoperative flexion angle. The installation angle of the tibial component in the sagittal plane is important.

Assessing coronal laxity in extension and flexion at a minimum of 10 years after primary total knee arthroplasty

PurposeFavourable long-term results after total knee arthroplasty (TKA) require appropriate soft tissue balance. However, the relationships between long-term results after TKA surgery and mediolateral laxities at extension and at 90° flexion remain unknown. This study therefore quantitatively assessed ligament balance at extension and at 90° knee flexion at least 10xa0years after primary TKA, as well as clarifying the relationships between long-term outcomes and mediolateral laxities.MethodsThis study included 49 knees (19 CR type and 30 PS type) of 33 patients followed up for at least 10xa0years after TKA at our hospital. Plain radiographs were obtained with about 150xa0N of varus or valgus stress using a Telos arthrometer at extension. At 90° flexion, epicondylar views were obtained under a 1.5-kg load and with about 10xa0kg of varus or valgus stress.ResultsLateral laxity of about 5° was observed in both extension and flexion, with total laxities of varus and valgus stress each less than 10°. Postoperative clinical outcomes were good, with significant improvements in extension angle, femorotibial angle, and KSS, and no loosening in any knee.ConclusionsGood long-term results of TKA can be obtained with a lateral laxity of about 5°, equivalent to that of healthy knees.Level of evidenceIII.

Comparison of Alignment Correction Angles Between Fixed-Bearing and Mobile-Bearing UKA

Good outcomes have been reported with both fixed-bearing and mobile-bearing unicompartmental knee arthroplasty (UKA). However, overcorrected alignment could induce the progression of arthritis on the non-arthroplasty side. Changes of limb alignment after UKA with both types of bearings (fixed bearing: 24 knees, mobile bearing: 28 knees) were investigated. The mean difference between the preoperative standing femoral-tibial angle (FTA) and postoperative standing FTA was significantly larger in mobile bearing UKA group. In fixed-bearing UKA, there must be some laxity in MCL tension so that a 2-mm tension gauge can be inserted. In mobile-bearing UKA, appropriate MCL tension is needed to prevent bearing dislocation. This difference in MCL tension may have caused the difference in the correction angle between the groups.

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.

Characteristics of medial plica syndrome complicated with cartilage damage

PurposeThis study was designed to evaluate the characteristics of patients with medial plica syndrome and associated cartilage damage.MethodsThe study subjects included 44 patients with 57 knees arthroscopically diagnosed with medial plica syndrome. Subjects were divided into those with severe cartilage damage, defined as International Cartilage Research Society (ICRS) stage 2 or higher, and those with mild cartilage damage, defined as ICRS stage 1 or lower. Local findings, period from onset to surgery, arthroscopic findings, and postoperative results were compared in the two groups.ResultsThe shapes of the medial synovial plica were types C and D of the Sakakibara classification in the severe group, and types A, B, and C in the mild group. Patellar ballottement tended to be more common in the severe than in the mild group (Pu2009=u20090.059). The duration from onset to surgery was significantly longer in the severe than in the mild group (29.0 vs. 11.6xa0months, Pu2009=u20090.043). Postoperative results were significantly better in the mild than in the severe group (Pu2009=u20090.0017).ConclusionsThe shape of the medial synovial plica and the duration between symptom onset and surgery were associated with cartilage damage. Surgical treatment should be considered when the medial synovial plica covers part of the anterior aspect of the medial femoral condyle or ruptures, or when pain persists over a long period, thus reducing the potential for cartilage damage.Level of Evidence: Level IV

Total Knee Arthroplasty for Neuropathic Joint Disease After Severe Bone Destruction Eroded the Tibial Tuberosity

This article describes a patient in whom total knee arthroplasty was performed for neuropathic joint disease secondary to diabetes mellitus after severe bone destruction eroded the tibial tuberosity. At initial examination, radiographs of the knee showed bone destruction in the medial and anterior regions of the tibia, and fine bone fragments were seen in the joint. Conservative therapy was performed using a brace. However, bone destruction gradually advanced, and 10 months after the initial examination, radiographs of the knee showed bone destruction in the lateral condyle of the femur and advanced bone destruction of the anterior tibia; the tibial tuberosity was missing. It is rare for the tibial tuberosity in the anterior tibia to disappear. If this happens, reconstruction is difficult and total knee arthroplasty becomes complicated. For the bone defect in the tibia, cement was used to recreate the shape of the anterior surface of the tibia. It was possible to minimize the volume of bone resection and morphologically reconstruct the tibial tuberosity. The patient recovered quickly. At postoperative week 5, the patient was able to walk using a cane. Thirty-six months after total knee arthroplasty, knee extension was 0°, flexion was 120°, extension lag was 5°, knee score improved from 40 points to 94 points, and functional score improved from 20 points to 75 points. However, long-term implant stability needs to be carefully monitored.

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

Abstract 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 (&Dgr;SEV) and FFV (&Dgr;FFV) 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 &Dgr;FFV was significantly greater than the &Dgr;SEV. &Dgr;SEV did not differ significantly among KL grades, but &Dgr;FFV 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.

Differences in patellofemoral alignment as a result of patellar shape in cruciate-retaining total knee arthroplasty without patellar resurfacing at a minimum three-year follow-up

BACKGROUNDnAlthough the patellofemoral (PF) joint shape of the femoral implant in a particular prosthetic design is identical, the articular surface shape of the patella varies between individuals. The present study investigated the effects of patellar shape on the postoperative PF joint in a cruciate-retaining total knee arthroplasty (CR-TKA) without patellar resurfacing and with at least three years of follow-up.nnnMETHODSnThis study investigated 76 knees of 62 patients who underwent CR-TKA without patellar resurfacing for varus osteoarthritis. Shape of the patella was classified in terms of the patellar facet angle (angle formed by the medial and lateral articular surfaces) as measured on axial plain X-ray. Subjects were divided into Group A with patellar facet angle ≤126° (34 knees) and Group B with patellar facet angle >126° (42 knees).nnnRESULTSnAnterior knee pain (AKP) was evident in four knees in Group A and one knee in Group B. Postoperative lateral patellar tilt angle was significantly larger in Group A than in Group B. Progression of osteosclerosis in the patella was present in 12 knees in Group A and three knees in Group B.nnnCONCLUSIONnThis study found that for a patella with a small patellar facet angle, lateral tilt of the patella was significantly increased after TKA, and a high rate of osteosclerosis was evident at >3years after operation. Performing TKA without patellar resurfacing on a patella with a small patellar facet angle may entail a higher risk of postoperative AKP; pre-operative evaluation of the shape of the patella is therefore important.

Early postoperative cartilage evaluation by magnetic resonance imaging using T2 mapping after arthroscopic partial medial meniscectomy

PURPOSEnThis study was performed to quantitatively evaluate postoperative changes in cartilage by T2 mapping after arthroscopic partial medial meniscectomy.nnnMATERIAL AND METHODSnThe study enrolled 17 patients with 20 knees that underwent arthroscopic partial medial meniscectomy. MRI was performed preoperatively and at six months postoperatively, with subjects evaluated by T2 mapping of the central part of the medial condyle of the femur in the sagittal plane. Regions of interest (ROIs) were set at 10 points between the point of intersection of the anatomical axis of the femur and the articular surface of the medial condyle and posterior area approximately 90 degrees to the anatomical axis. Pre- and postoperative T2 values at each ROI were evaluated.nnnRESULTSnPostoperative T2 values were significantly longer than preoperative values at approximately 20, 30, 40, and 50 degrees to the anatomical axis of the femur. The maximum change between pre- and postoperative T2 values was +6.65% at 30 degrees to the anatomical axis.nnnCONCLUSIONSnMechanical stress at positions approximately 20, 30, 40, and 50 degrees relative to the anatomical axis of the femur increased soon after arthroscopic medial meniscectomy. These findings indicate the start of degeneration, via disorganization of collagen arrays, of the articular cartilage and increased water content.