Proper rotational alignment of the tibial component in total knee arthroplasty (TKA) could be achieved using several techniques. The self adjustment methodology allows the alignment of the tibial component under the femoral component after several flexion-extension movements. Our hypothesis was that this technique allowed a posterior tibial component alignment parallel to the femoral component posterior bicondylar axis. The aim of this study was to access this hypothesis using a post-operative CT-scan study. This prospective CT-scan study involved 94 TKA. Theses TKA were divided in two groups: group1: 50 knees with a pre-operative genu varum deformity (mean HKA: 172.2°), operated using a medial parapatellar approach, and group 2: 44 knees with a preoperative valgus deformity (mean HKA: 188.7°), operated using a lateral parapatellar approach. Four measures were done on each post-operative CT-scan: angle between anatomical transepicondylar axis and femoral component posterior bicondylar axis (FCPCA), angle between FCPCA and tibial component marginal posterior axis, angle between tibial component marginal posterior axis and bony tibial plateau marginal posterior axis (BTPMPA), angle between transepicondylar axis and tibial component marginal posterior axis. Each measure was repeated, after one month by the same independent observer. Statistical evaluation used non-parametric Wilcoxon–Mann–Whitney test to compare each group of measures, and intraobserver reproducibility was assessed using ANOVA test, with an error rate of 5%.Introduction
Materials and Methods
The bare area of the humeral head is limited in front by the cartilage and backwards by the insertion of the Infra Spinatus tendon. There are few references in the current literature. The aim of this work was to precise the anatomic description of the bare area and to compare the size of this area in patients with anterior shoulder instability and patients without anterior shoulder instability. We have proceeded first to an anatomic study to precise the limit of the bare area. The second part of this study was a retrospective and prospective comparative arthro CT-scan study in two groups of patients. The first group (group 1) had 48 patients, going to have anterior instability surgery. The second group (group 2) had 38 patients, without shoulder instability. Mean age was respectively 28.2 years (range: 19–48) in group 1; and 39.3 years (16–69) in group 2. The size of the bare area was measured on the axial injected CT cut passing by the larger diameter of the humeral head, The size of the bare area was definite by the angle between the line connecting the centre of the head to the posterior limit of the cartilage and the line connecting the centre of the head to the anterior point of the Infra Spinatus tendon. The reproducibility of the measure has been evaluated by a Bland and Altman test and an intra class correlation test. The measures were realised by two independent surgeons in a blind manner. The results where compared by a Student test with a threshold at 5%. In the anatomic part of this study, the average angle of the bare area was 32.7° equal to 13.7mm wide. Mean intraobserver variability was 4° (range: 0 to 20°) (NS) and mean interobserver variability was 4° also (range: 0 to 20°) (NS). Mean size of the bare area was 49.6° eaqual to 19.8mm wide [range 25° to 70°] in group 1 and 33.2° equal to 13.5mm wide [range 21° to 60°] in group 2 (p< 0,05).Material and method
Results
Ligamentoplasty resorting to autogenous bone-tendon-bone grafts represents an effective long-lasting remedy to the anterior instability of the knee. If this indication has proved effective regarding the stability, the sampling of a piece of the extensor system often brings about a certain morbidity. Various approaches have been advocated concerning the tendinous site: some leave it open, others suture one of the peripheral thirds of the remaining tendon to the other. These various technical choices are likely to alter the morbidity and the patellar level, together with the tissue nature of the site of sampling. The purpose of this study was to assess the effect of the suture of the site of sampling on the patellar level, after a ligament plastic surgery resorting to a bone-tendon-bone graft. To this end, a group of 40 patients whose tendinous site of sampling had been left open was compared to another group of patients whose peripheral thirds of the remaining patellar tendon had been sutured one to the other. The patellar level was assessed with Caton’s, Black-burne’s and Insall and Salvati’s methods on x-rays first taken before and then 6 months after the operation. To analyse the results, we resorted to the reduced gap method and the Student-Fisher one for the comparison between quantitative and qualitative variables, and to the correlation coefficient method for the comparison between quantitative variables. The post-operative values of Caton’s, Blackburne’s and Insall and Salvati’s indexes were respectively 1.002, 0.844, and 1.188 for patients whose patellar tendon had been left open, and 1.023, 0.882, and 1.184 for patients whose tendinous edges had been sutured up. The discrepancy between those values had no statistical significance. Suturing the site of sampling in a bone-tendon-bone ligament plastic surgery has no effect on the patellar level.
Meniscus repair is now an accepted procedure, but many questions remain, regarding the results, indications versus meniscal resection. How to assess the results of meniscal repair? Clinical results doesn’t allow to assess the healing rate. Some failure of healing can be asymptomatic. There is thus a need for an objective assessment of the healing process: by arthroscopy (but it is invasive); by MRI but the hypersignal in the meniscus area is difficult to interpret. The best way seems to be arthro CT, even if it is a quite invasive technique.
1. Location of the lesion. In case of lesions in the red-red zone or red-white zone: the healing potential is good ameniscectomy would be total and would lead to secondary degenerative changes. it is thus the best indications for meniscal repair In case of lesions in the white-white zone: the healing potential is poor the meniscectomy would be partial with usual good long term results. Indications for meniscal repair should be very selective in this occurrence 2. Etiology 2.1. ACL Tears Meniscectomy is the key of degenerative process after ACL rupture. ACL reconstruction is able to preserve meniscal status We must thus preserve the menisci as much as possible: by doing a meniscal repair in case of unstable extended lesions by abstention if he meniscal is table. In all the cases, ACL should be reconstructed. Results of meniscal repair in this context are good both in terms of clinical results and healing rate Isolated meniscal repair should be only considered in presence of 4 criteria: symptomatic meniscal lesion, no functional instability, non repairable meniscal lesion, low demanding patient 2.2. Stable Knees Meniscectomy remains the most frequent procedute in this condition with good functional results. But, according to the long term FU results (>
10year) (multi-centre study of the SFA 1996), the rate of asymptomatic knees is only 60% on the medial side, and 50% on the lateral side. The rate of joint line narrowing is 28% on the MM and 40% on the lateral side. The recovery after lateral meniscectomy is often long with a high rate of rearthroscopy (14%). There is a specific complication on the lateral side: rapid chondrolysis by young patients. Meniscal repair should be thus proposed as often as possible The best indcation is a peripheral vertical lesion by a young patient. The rate of secondary meniscectomy is about 10% but the rate of complete healing is only 50 to 60% according to the literature. Prognostic factors are: time to surgery: recent lesions have a better prognosis (12 weeks ?) extension of the lesion side of the lesion: lateral lesion is better than medial one. Intrameniscal horizontal cleavage grade 2 lesion by young patients is a specific indication which gives good results and avoids a total meniscectomy.
Meniscal repair should be recommended for red-red or red-white zone to preserve the meniscus and thus the cartilage, specially on ACL unstable knees, lateral side, young patients (children+++). But many questions remain: which strength do we need ? what about shear forces is there any secondary degenerative changes of the meniscal tissue with an increasing risk of iterative tear which long term results with the new devices ?