Postoperative Posterior Tibial Slope Research Articles

Blackburne-Peel ratio predicts patients' outcomes after total knee arthroplasty.

Alterations in patellar height and posterior tibial slope (PTS) are frequently measured radiographic parameters associated with postoperative impairments after total knee arthroplasty (TKA). Few studies correlate the clinical outcome of TKA with the radiological indices. Both the modified Insall-Salvati ratio (mISR) and the Blackburne-Peel ratio (BPR) were hypothesised to correlate with the clinical outcome after TKA. A total of 282 computer navigated primary LCS®-TKAs, implanted in our institution from 2008 to 2012, were included. Data (ROM, FJS-12, WOMAC, and revision surgery) were collected independently and prospectively. Patellar height (mISR, BPR), joint-line position, and PTS were measured on pre- and postoperative radiographs. Bivariate and multiple regression analyses were performed. Mean mISR (1.5-1.4) and BPR (0.8-0.6) decreased from preoperatively to 1year follow-up. Mean joint-line shift in a cranial direction was 2mm after TKA implantation. Analysis of dichotomous variables (presence of PB and PPB or not) only showed significantly lower flexion in patients with PPB (p < 0.001). However, multiple regression revealed that BPR was a significant positive independent predictor for FJS-12 (p = 0.016) and flexion (p < 0.001) at 1year follow-up. Postoperative PTS (p < 0.01) and initial patella height (p < 0.001) were both predictive for BPR at follow-up, while the joint-line height was not. The BPR is a useful and reliable radiographic parameter to predict patient outcomes 1year after primary navigated TKA. Lowering the BPR should be avoided, as this may lead to significant restrictions in terms of ROM and PROMs. Level 3.

Mid-Term Clinical Outcome and Reconstruction of Posterior Tibial Slope after UKA.

Unicompartmental knee arthroplasty (UKA) has gained growing popularity over the last decades. The posterior tibial slope (PTS) has been shown to play a significant role for knee biomechanics and is thought to be crucial for clinical function of the UKA. We evaluated the clinical outcome at mid-term follow-up after UKA. Furthermore, the reconstruction of the individual PTS was analyzed. A total of 91 consecutive patients undergoing medial UKA for osteoarthritis were included. Patients were contacted by telephone for a survival analysis at a minimum of 30 months after surgery. Patient-oriented questionnaires and Knee Osteoarthritis Outcome Score (KOOS) were obtained. A retrospective chart review and radiological analysis of component alignment were performed for all patients before and at 6 weeks after surgery. Of 91 patients (93 knees) undergoing UKA, 69 patients (70 knees) were available for clinical follow-up after a mean of 56.0 (range 31-81) months post-surgery. The clinical results of the examined patients in the present study showed mean subscale scores of the KOOS and Western Ontario and McMaster Universities Osteoarthritis Index between 71 and 91%. Overall 7 of 91 patients were revised during the course of follow-up period and underwent total knee arthroplasty. A Kaplan-Meier analysis showed a survival rate for UKA of 90.5% after 48 months. Calculated implant survival was 75.9 months (95% confidence interval 72.3-79.6) at the mean. The radiographic analysis of pre- and postoperative PTS showed no differences (p = 0.113).UKA for osteoarthritis of the medial knee compartment shows encouraging clinical results at mid-term follow-up. The individual PTS could be reconstructed within acceptable ranges. This is a retrospective therapeutic study with Level IV.

Influence of tibial component slope on short-term clinical outcome for Oxford unicompartmental knee arthroplasty

Objective: To investigate the effects of tibial component slope change after microplasty (MP) Oxford unicompartmental knee arthroplasty (UKA) on short-term clinical outcome. Methods: A total of 116 patients(128 UKAs)underwent UKA in Department of Orthopaedic Surgery of China-Japan Friendship Hospital between January 2014 and December 2015 were retrospectively reviewed. Totally 100 patients (108 UKAs) were finally included in the study. There were 31 males and 69 females, aging from 47 to 90 years (mean 67.2 years). The mean height was (161.9±8.4) cm and the mean body mass index (BMI) was (26.2±3.3) kg/m(2). The posterior tibial slope (PTS) at preoperative and postoperative were measured on the lateral radiograph. The postoperative PTS were divided into five groups (<3°, 3° to 5°, 5° to 7°, 7° to 9° and>9°). The Oxford Knee Score (OKS) was recorded. Pearson correlation analysis, ANOVA and t test were used to analyze data. Results: All operations were successfully accomplished and there were no transfusion, infection, thrombus and other complications. There was 1 patient accepted revision because of bearing dislocation. Compared to preoperative, the PTS decreased (6.5°±2.2° vs.9.6°±3.4°) postoperative, there was statistical difference (t=9.053, P<0.01). Only 3 patients were beyond the recommended range (2° to 12°). A total of 82 patients (86 UKAs) were followed up. The follow-up time was 1 to 2.9 years (mean 2 years). The OKS was 43.0±4.1 (mean 31 to 48). The PTS increased in 12 patients (12 UKAs) postoperative, the mean OKS was 40.5±5.2. The PTS decreased in 70 patients (74 UKAs), the mean OKS was 43.4±3.8. There were significant difference in OKS (t=2.347, P=0.021). There were no significant difference in OKS between the five groups. There were positive correlation between postoperative PTS and preoperative PTS (r=0.201, 95%CI: 0.001 to 0.396, P=0.037), there were no correlations between postoperative PTS and hight and BMI. There were negative correlations between OKS and postoperative PTS (r=-0.255, 95%CI: -0.063 to -0.427, P=0.018) and PTS change (r=-0.292, 95%CI: -0.08 to -0.475, P<0.01). Conclusions: Satisfying PTS can be obtained by use of Oxford MP instrumentation. The clinical outcome of the postoperative PTS decreased was relatively better. Too large posterior slope of the tibial implant should be avoided.

Is it possible to avoid posterior tibial slope increase in open-wedge high tibial osteotomy?

Aim:Posterior tibial slope has shown to be increased with open-wedge high tibial osteotomy (OWHTO) which may lead to an increase in loading of the anterior cruciate ligament and causing patellofemoral problems in return. In this case series, patients with an OWHTO performed posteromedial to the medial collateral ligament (MCL), keeping it intact was investigated. The aim of this study was to evaluate the influence of this technique on the posterior tibial slope.Methods:Thirty knees (15 right, 15 left) of 28 patients (22 women, 6 men) with a mean age of 53.57±5.9 years who had an OWHTO between January 2014 and February 2016 were included in this study. Surgical technique: A proximal tibial osteotomy is performed posteromedial to MCL keeping it intact. Following the osteotomy, distraction is also performed from the posteromedial aspect of tibia. Fixation is achieved utilizing TomoFix plate. Radiological evaluation: Preoperative and postoperative mechanical axes (MA) were measured on standard weight bearing long axis x-rays. Preoperative and postoperative posterior tibial slope angles were measured on lateral x-rays using three different Methods: the angles between medial tibial plateau and (1) posterior tibial cortex, (2) tibial proximal anatomical axis, and (3) posterior fibular cortex were measured. The correlations of three different measurement methods were analyzed. Patients were grouped according to preoperative MA deviations and postoperative MA changes (either <10º or >=10º). The posterior tibial slope changes were compared between groups. Statistical analyses: All statistical analyses were performed utilizing SPSS 18.0.Results:Mean preoperative and postoperative MA deviations were 9.81°±4.94° and -2.72°± 2.69° respectively. The mean correction angle of MA of lower extremity was 12.62°±4.58°. The three methods used to measure the posterior tibial slope angles were found to be highly correlated with each other ((1) and (2) r=0.961; (1) and (3) 0.906; (2) and (3) 0.934; p values <0.0001). Preoperative mean posterior tibial slope angles were 9.50º±4.47°, 11.51º± 4.50°, and 10.80º±4.58°; postoperative angles were 6.10º±4.23°, 8.78º±4.57° and 8.11º±4.55°, respectively. Posterior tibial slope angle was significantly decreased postoperatively with respect to all three methods (p <0.0001). The changes in the posterior tibial slope was not statistically significant between the groups with preoperative <10º and >=10º deformities (p values 0.861, 0.723, 0.727, respectively).Conclusions:Posterior tibial slope was found to be decreased with this posteromedial OWHTO technique. This technique offered the advantage of preserving the posterior tibial slopes postoperatively even in highly deformed knees which necessitated higher degrees of corrections in the mechanical axes.

Sagittal osteotomy inclination in medial open-wedge high tibial osteotomy.

Unlike postoperative changes in posterior tibial slope after medial open-wedge high tibial osteotomy, sagittal osteotomy inclination has not been examined. It has been recommended that the osteotomy line in the sagittal plane be parallel to the medial posterior tibial slope. The purpose of this study was to determine the frequency of parallel osteotomy in medial open-wedge high tibial osteotomy. To determine the sagittal osteotomy inclination, the angle between the medial joint line and the osteotomy line was measured in the lateral radiograph. A positive angle value indicates that the osteotomy is anteriorly inclined relative to the medial posterior tibial slope. Correlation between the sagittal osteotomy inclination and posterior tibial slope was also evaluated. The mean sagittal osteotomy inclination was 15.1±7.5°. The majority 87.1% of knees showed an anterior-inclined osteotomy. There was a significantly positive correlation between the postoperative posterior tibial slope and the sagittal osteotomy inclination (r, 0.33; 95% confidence interval (CI) 0.19-0.46; P<0.001). The postoperative change in posterior tibial slope also showed a significantly positive correlation with the sagittal osteotomy inclination (r, 0.35; 95% CI 0.21-0.47; P<0.001). Although parallel osteotomy in the sagittal plane relative to the medial joint line was planned, only 12.9% of cases achieved osteotomy parallel to the medial posterior tibial slope in the sagittal plane. Because of high rate of the anterior-inclined osteotomy and their correlations with posterior tibial slope, surgeons should make all efforts to perform parallel osteotomy relative to medial posterior tibial slope. IV.

Effect of Posterior Tibial Slope on Flexion and Anterior-Posterior Tibial Translation in Posterior Cruciate-Retaining Total Knee Arthroplasty

Reduced posterior tibial slope (PTS) and posterior tibiofemoral translation (PTFT) in posterior cruciate-retaining (PCR) total knee arthroplasty (TKA) may result in suboptimal flexion. We evaluated the relationship between PTS, PTFT, and total knee flexion after PCR TKA in a cadaveric model. We performed a balanced PCR TKA using 9 transfemoral cadaver specimens and changed postoperative PTS in 1° increments. We measured maximal flexion and relative PTFT at maximal flexion. We determined significant changes in flexion and PTFT as a function of PTS. Findings showed an average increase in flexion of 2.3° and average PTFT increase of 1mm per degree of PTS increase when increasing PTS from 1° to 4° (P<.05). Small initial increases in PTS appear to significantly increase knee flexion and PTFT.

The influence of surgical factors on dislocation of the meniscal bearing after Oxford medial unicompartmental knee replacement: a case-control study.

The aim of this study was to evaluate the risk factors for dislocation of the bearing after a mobile-bearing Oxford medial unicompartmental knee replacement (UKR) and to test the hypothesis that surgical factors, as measured from post-operative radiographs, are associated with its dislocation From a total of 480 UKRs performed between 2001 and 2012, in 391 patients with a mean age of 66.5 years (45 to 82) (316 female, 75 male), we identified 17 UKRs where bearing dislocation occurred. The post-operative radiological measurements of the 17 UKRs and 51 matched controls were analysed using conditional logistic regression analysis. The post-operative radiological measurements included post-operative change in limb alignment, the position of the femoral and tibial components, the resection depth of the proximal tibia, and the femoral component-posterior condyle classification. We concluded that a post-operative decrease in the posterior tibial slope relative to the pre-operative value was the only significant determinant of dislocation of the bearing after medial Oxford UKR (odds ratio 1.881; 95% confidence interval 1.272 to 2.779). A post-operative posterior tibial slope < 8.45° and a difference between the pre-operative and post-operative posterior tibial slope of > 2.19° may increase the risk of dislocation.

Clinical Results Associated with Changes of Posterior Tibial Slope in Total Knee Arthroplasty

PurposeThe purpose of this retrospective study is to investigate the effect of posterior tibial slope (PTS) on clinical results in total knee replacement arthroplasty (TKA).Materials and MethodsWe analyzed 801 knees in 768 patients who underwent TKA using a cruciate-retaining prosthesis for osteoarthritis from July 2003 to July 2009. PTS was measured on simple X-ray films and patients were divided into 5 groups, according to the change in PTS that was calculated by subtracting the preoperative from the postoperative PTS: group 1, >3°; group 2, 3° to 1°; group 3, 1° to -1°; group 4, -1° to -3°; and group 5, <-3°. We analyzed the correlations between the change in PTS and clinical results, such as Knee Society knee score, Knee Society functional score, Feller patella score, Kujala score, visual analog scale score, range of motion, and complications.ResultsThere was no statistically significant intergroup difference; however, Feller patella score and Kujala score were significantly different in groups 2 and 3. There were no complications, such as progressive loosening of implants, fractures of polyethylene inserts and wears.ConclusionsClinically meaningful improvement was observed in all patients after TKA. Groups 2 and 3 (3° to -1°) showed significant improvement compared to the other groups.

The Correlation between Posterior Tibial Slope and Maximal Angle of Flexion after Total Knee Arthroplasty

PurposeThe purpose of this study was to evaluate the correlation between the posterior tibial slope and the maximal angle of flexion after total knee arthroplasty.Materials and MethodsSeventy nine cases (63 patients, 60 females and 3 males), which received total knee arthroplasty with the Nexgen LPS system from Jan 2001 to Jan 2004, were enrolled. We divided all cases into two subsets in two ways. Firstly, group A (up to 10°, 44 cases) and group B (over 10°, 35 cases) were divided according to the mean value of the postoperative posterior tibial slope. Secondly, group α (up to -4°, 39 cases) and group β (over -4°, 40 cases) were divided according to the mean difference between the preoperative posterior tibial slope and the postoperative posterior tibial slope. We compared the maximal angle of flexion between group A and group B, group α and group β, respectively.ResultsThere was no significant difference between group A and group B, and also between group α and group β in terms of maximal angle of flexion.ConclusionsThere was no significant correlation between the postoperative posterior tibial solpe and the maximal angle of flexion.

The correlation of correction magnitude and tibial slope changes following open wedge high tibial osteotomy

We investigated whether there is a correlation between coronal plane correction magnitude and tibial slope in patients treated with medial open wedge high tibial osteotomy (OWHTO) and also measured changes in patellar height. Thirty-four knees treated with for varus deformities were retrospectively reviewed and the follow-up period of the patients was averaged 24.1 months. Preoperative and postoperative measurements of the Hospital for Special Surgery (HSS) score, Insall-Salvati index, posterior tibial slope angle, mechanical axis deviation, proximal medial tibial angle (PMTA) was used to determine. All patients had a significant increase in their HSS score postoperatively (P < 0.0001). There was no significant correlation between the differences in patellar heights (P = 0.368). The mechanical axis deviation was altered by a mean of 25.5 +/- 10.9 mm and the difference was statistically significant (P < 0.05). The mean posterior tibial slope angle on preoperative radiographs was 9.0 +/- 5.1 degrees ; on postoperative radiographs it was 11.7 +/- 5.7 degrees and the difference was statistically significant (P < 0.007). Seventeen knees (50%) demonstrated postoperative posterior tibial slope angle increases; 7 knees (21%) had a decrease in this angle, while 10 knees (29%) showed no change. Statistical analyses revealed that the mechanical axis deviation was not correlated with change in tibial slope (P = 0.837). Although we could not find a correlation between tibial slope change and the amount of coronal correction, 50% of our patients demonstrated increased tibial slope.

The Change of the Posterior Tibial Slope after Cruciate Retaining Total Knee Arthroplasty

Purpose: To analyze the preand postoperative posterior tibial slope angle (PSA) of performing cruciate-retaining total knee arthroplasty (TKA) and to identify the ideal value of the PSA in relation to the clinical results. Materials and Methods: From June 1999 to May 2005, 202 TKA with a NexGenR cruciate-retaining knee were performed in 160 patients. The mean follow-up period was 39.8 months. The preand postoperative PSA referenced by the proximal tibial medullary canal (PSA-A) and the proximal tibial anterior cortex (PSA-B) were measured by two independent observers. The knee and function scoring system of the American Knee Society and the range of motion of the knee at the last follow-up were evaluated as the clinical results. Results: The mean PSA-A was 11.4±4.8 preoperatively and 6.0±2.8 postoperatively, and the mean PSA-B was 13.6±4.9 preoperatively and 8.1±2.9 postoperatively. The difference between the preand postoperative PSA increased as the preoperative PSA-A changed from 6.0 and the PSA-B changed from 8.1; these findings showed statistical significance based on a simple linear regression (PSA-A: r= 0.837, p=0.000; PSA-B: r=0.834, p=0.000). The knee and function score of American Knee Society improved respectively from 62.9 and 55.8, preoperatively, to 97.4 and 89.7 respectively, at the last follow-up. The range of motion of the knee joint was 128.0 preoperatively and 129.7 at the last follow-up. Conclusion: In cruciate retaining total knee arthroplasty, PSA-A is mostly distributed within 3.2-8.8, and a reasonable range of PSA-A is 6.0±2.8.

Proximal Tibial Opening Wedge Osteotomy as the Initial Treatment for Chronic Posterolateral Corner Deficiency in the Varus Knee

Background Nonoperative treatment of posterolateral knee injuries tends to yield poor results. In patients with chronic posterolateral knee injuries, failure to correct genu varus alignment will often result in failure of the posterolateral knee repair or reconstruction. Purpose To prospectively assess the functional outcomes of patients with combined grade 3 posterolateral instability and genu varus alignment initially treated with a proximal tibial opening wedge osteotomy. Study Design Cohort study (prognosis); Level of evidence, 2. Methods Twenty-one patients with combined chronic posterolateral corner deficiency and genu varus alignment were initially treated with a proximal tibial opening wedge osteotomy and observed prospectively. Second-stage ligamentous reconstruction was performed in patients with continued clinical and functional instability after the osteotomies had healed and they had undergone at least 3 months of rehabilitation. Results At a mean follow-up of 37 months, 8 of 21 patients (38%) had sufficient improvement in knee function that a subsequent posterolateral corner reconstruction was not necessary. There was a significant difference in coronal alignment between the preoperative and postoperative mechanical axis action point. There were no significant differences in the preoperative and postoperative posterior tibial slope. Thirteen patients underwent a second-stage ligament reconstruction at an average of 13.8 months after the initial osteotomy procedure. Final postoperative Cincinnati Knee Rating System scores were significantly lower for those patients who required a subsequent posterolateral corner reconstruction than for those patients who did not have a reconstruction. The P value for the preoperative differences between groups was not significant (P = .11). Seven of 9 patients with high-velocity knee injuries required a second-stage reconstruction. Ten of 14 patients (71%) with multiligament knee injuries required a posterolateral corner reconstruction. In contrast, 4 of 6 patients (67%) with an isolated posterolateral corner injury did not require a second-stage ligament reconstruction. Conclusion Proximal tibial opening wedge osteotomy can be an effective first method of treatment for patients with chronic combined posterolateral knee injuries and genu varus alignment. Patients with low-velocity knee injuries and isolated chronic posterolateral knee injuries may not require a second-stage soft tissue ligament reconstruction after healing the osteotomy and undergoing a program of rehabilitation.

Early Failure of Unicompartmental Knee Arthroplasty

We are reporting the relatively poor results obtained in patients receiving a unicompartmental knee arthroplasty (UKA). Thirty-six patients underwent 39 UKAs from December 2002 to June 2004. All received a DePuy Preservation design (DePuy, Warsaw, In) with an all-poly tibial component. The patients' mean age was 60 years, with an equal distribution of men to women. Of the 39 UKAs, 15 (38%) failed at 9 to 12 months postoperative. All the failures were secondary to loosening of the femoral component. No correlation to failure was found between preoperative antero-posterior (AP) angle, postoperative AP angle, amount of correction obtained, postoperative posterior tibial slope, lateral femoral component alignment, postoperative range of motion, sex, or size of the patient.