Preoperative Anterior Knee Research Articles

Effectiveness of Patellar Replacementin Total Knee Arthroplasty: Randomized, Prospective Study using Simultaneous Bilateral Total Knee Arthroplasty

Purpose : This study evaluated the clinical and radiological results of a randomized clinical trial of patella resurfacing. Materials and Methods : A blinded, prospective study was carried out for 20 patients who underwent bilateral TKA with one patellar side being resurfaced from Jan. 2002 to Jun. 2003. The clinical results were assessed using the knee society clinical rating system, patellar score and patient-satisfaction score. Radiologically, patellofemoral congruency was assessed by measuring the patellar displacement in the skyline view. Results : There were no significant differences between the resurfaced and non-resurfaced knees with respect to the overall knee society knee scores or the patellar scores. In the patient-satisfaction scale, 2 out of 4 knees with anterior pain postoperatively were unsatisfactory to the patients. The average patellar congruency in the non-resurfacing/resurfacing group was 98.8%/98%. Conclusion : The clinical and radiological results after TKA were not associated with patellar resurfacing. It appears that a variety of factors such as preoperative anterior knee pain, pathological lesion and alignment of patella, and the surgical technique are related to the postoperative results.

Fiabilité de l’arthromètre KT-1000 pour la mesure de la laxité antérieure du genou: Comparaison avec l’appareil Télos à propos de 147 genoux

Purpose of the study The purpose of this study was to compare the reliability and the reproducibility of both the KT-1000 arthrometer (Medmetric) and Telos for measuring anterior knee laxity. The Telos was used as the reference technique. Material and methods Criteria for inclusion were preoperative anterior knee laxity, normal contralateral knee, and intra-articular surgery to reconstruct the anterior cruciate ligament. Between January 1 st, 2000 and October 31 st, 2001, 147 patients were operated on for knee instability using an autograft (BPTB or hamstring tendons). For each patient, comparative measurements were made for both knees preoperatively and postoperatively with an average follow-up of 16 months. Measurements with the KT-1000 apparatus were made with forces of 67 N, 89 N, 134 N and manual maximal force. For the Telos, a force of 250 N was used as recommended by the manufacturer. We also evaluated intraobserver variation between the two devices. Results The anterior translation preoperatively as measured by the KT-1000 at 89N was 4.2 ± 2.4 mm and 6.3 ± 2.5 mm at maximal manual force. The result for Telos was 3.0 ± 3.6 mm. The data scatter obtained with Telos was wider than with KT-1000 (p < 0.03). The sensitivity of Telos was 72% with 28% false negatives. With KT-1000, sensitivity increased as tensile force increased. Sensitivity was 65% at 89N, 73% at 134N and 92% at maximal manual force. The concordance between the KT1000 and Telos data was low for either preoperative (10%) or postoperative (30%) measurements. Discussion and conclusion In this study, the results of sensitivity and reproducibility as well as the minimal scatter of the values demonstrated the reliability of KT-1000 for measuring anterior translation of the knee. We recommend routine use of the KT-1000 device for measuring knee laxity. The low sensitivity and the high rate of false negative observed with Telos raises the question of its use a reference technique.

INDICATIONS FOR PATELLAR RESURFACING IN TOTAL KNEE ARTHROPLASTY

The management of the patella in total knee arthroplasty (TKA) traditionally has been one of three options: always resurface, never resurface, or selectively resurface the patella. Historically, implant design and surgical technique did not completely address the patellofemoral articulation. Increased understanding of patellofemoral anatomy, biomechanics, implant design, and surgical technique have led to an improvement in the previously reported high rate of patellofemoral complications associated with TKA. Traditional indications for patellar resurfacing, including age, weight, gender, patellar anatomy, quality of articular cartilage, radiographic findings, and the presence of rheumatoid arthritis deformity and preoperative anterior knee pain continue to be debated. Anterior knee pain before and after TKA must not always be presumed to be secondary to a patellofemoral resurfacing/nonresurfacing etiology, and other factors may play a role in the dynamic development of anterior knee pain after TKA. The decision to resurface the patella in TKA remains controversial, and the results of longer-term randomized controlled trials will improve understanding of this complex issue in the future.

前十字靭帯再建術後の前方動揺性に及ぼす患者側の要因について

We performed multivariate analyses on individual factors such as gender, age, preoperative anterior knee laxity, presence of resection of the posterior part of meniscus, and presence of genu recurvatum that may affect anterior knee laxity after anterior cruciate ligament (ACL) reconstruction using the hamstring tendons. Thirty-four males and forty females were included in this study except for patients with multiple ligament injuries of the knee, bilateral or revision ACL reconstruction. All patients underwent identical surgery and were treated with the same postoperative management. Their anterior knee laxity was measured using a KT-1000 arthrometer under manual maximum force before and one year after the reconstruction. The results showed that the regression coefficient was 0.432 and there was significant correlation between postoperative anterior laxity and gender, preoperative anterior laxity, resection of the posterior part of meniscus, and genu recurvatum. From these results, we concluded that it is important to plan graft selection, surgical technique, and postoperative management for each patient to achieve better postoperative anterior knee laxity.

Patellar Resurfacing in Total Knee Arthroplasty

Whether to resurface the patella during a primary total knee arthroplasty performed for the treatment of degenerative osteoarthritis remains a controversial issue. Parameters that have been suggested as being useful in guiding this decision include patient height and weight, the presence of anterior knee pain preoperatively, and the grade of chondromalacia encountered intraoperatively. The purpose of this study was to determine whether these parameters were predictive of the clinical result following total knee arthroplasty with or without patellar resurfacing. Eighty-six patients (118 knees) undergoing primary total knee arthroplasty for the treatment of osteoarthritis were enrolled in a prospective, randomized, double-blind study. All patients received the same posterior-cruciate-sparing total knee prosthetic components. Patients were randomized to treatment with or without resurfacing of the patella. Evaluations consisted of the determination of a Knee Society clinical score, the completion of a patient satisfaction questionnaire, specific questions relating to patellofemoral symptoms, and radiographs. Sixty-seven patients (ninety-three knees) were followed for a minimum of five years (range, sixty to eighty-four months; average, 70.5 months). With the numbers available, there was no significant difference between the groups treated with and without resurfacing with regard to the overall Knee Society score or the pain and function subscores. Obesity, the degree of patellar chondromalacia, and the presence of preoperative anterior knee pain did not predict postoperative clinical scores or the presence of postoperative anterior knee pain. The occurrence of anterior knee pain could not be predicted with any clinical or radiographic parameter studied. On the basis of these results, it seems likely that postoperative anterior knee pain is related either to the component design or to the details of the surgical technique, such as component rotation, rather than to whether or not the patella is resurfaced.

Preoperative anterior knee laxity did not influence postoperative stability restored by anterior cruciate ligament reconstruction

Summary: Eighty-six chronic anterior cruciate ligament (ACL)-injured patients were quantitatively measured for anterior knee stability preoperatively and at 2 years or later (mean, 30 months) postoperatively to examine the influence of preoperative knee laxity on the postoperative knee stability restored by the ACL reconstruction using multiplied hamstring tendon graft. The patients were divided into 3 groups according to the preoperative injured minus normal anterior laxity difference (AL-D) (group I [n = 27] <5 mm, group II [n = 48] 5 to 9 mm, group III [n = 11] >10 mm). The 3 groups were comparable in gender, age, meniscal status, graft excursion measured during operation, time from injury to operation, and activity level. The postoperative AL-D in group I was 0.8 ± 1.7 mm, that in group II was 1.1 ± 1.6 mm, and in group III was 1.5 ± 1.4 mm. There were no significant statistical differences among these 3 groups. With our surgical technique including postoperative rehabilitation, patients with severe instability could be treated successfully without needing any additional procedures such as extra-articular augmentation or specially designed postoperative rehabilitation programs.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 16, No 5 (July), 2000: pp 477–482