Total knee replacement following high tibial osteotomy

There have been conflicting reports in the literature regarding the results of post high tibial osteotomy knee arthroplasty. This study aims to assess the clinical and radiological results as well as patient satisfaction following post high tibial osteotomy knee arthroplasty and to identify the variables affecting the results. A total of 29 cases of post osteotomy knee arthroplasties were retrospectively analyzed. Preoperative and postoperative range of movement and deformity were recorded with knee scores at latest follow-up. Weightbearing radiographs were taken preoperatively and at latest follow-up. Patients were asked if they were satisfied with their results. Average follow-up was 7.5 years with an average interval between osteotomy and knee arthroplasty of 4.7 years. Average age at osteotomy was 62.5 years. Seventeen patients had Maquet's dome osteotomy and 12 had closing wedge osteotomy. The average knee score was 117.4. Overall 5 (17.2%) patients had a poor result. There was a significantly greater pre-osteotomy subluxation (9 mm) in the failed knees compared to the successful arthroplasties (3.64 mm) with p = 0.033 using the Mann-Whitney U test. This has to be tempered by the fact that numbers were small. Failed arthroplasties had a valgus cut of the tibia (1.5 degrees) compared to either a neutral or slight varus cut in successful arthroplasties (average 2.42 degrees varus). Lateral translation of tibial tray was greater in the failed knees whereas posterior translation was greater in the successful knees. However, differences in tibial tray angle and translation were not statistically significant. Four (21.05%) cases went on to revision of their arthroplasty in less than 8 years, 2 for painful valgus instability. This study concludes that post high tibial osteotomy knee arthroplasty is a technically demanding operation with altered anatomy and significant balancing problems. Results of knee arthroplasty after high tibial osteotomy are inferior to that of primary arthroplasties and the amount of lateral subluxation prior to surgery may adversely affect results.     

High tibial valgus osteotomy for medial gonarthrosis: a 10- to 21-year study

This retrospective study reviewed the long-term experience with high tibial osteotomy and determined which factors influence the results. Between 1980 and 1989, 120 closing wedge high tibial osteotomies for varus gonarthrosis were performed in 102 patients. Twenty-nine knees were excluded because the patients died (17 knees), were bedridden (7 knees), or lost to follow-up (5 knees). Thirty of the remaining 91 knees had a conversion to total knee replacement (TKR) after 11 years on average, leaving 61 knees with a high tibial osteotomy available for clinical and radiographic evaluation at an average follow-up of 15 years (range: 10-21 years). Of the 91 knees, excellent/good results were found in 49% and fair/poor in 51%. Anatomical femorotibial angle in the 61 knees at follow-up averaged 4.7 degrees +/- 5 degrees of valgus (range: 3 degrees varus to 23 degrees valgus). Alignment obtained at consolidation changed with varus recurrence at follow-up in 14% of 61 knees and did not correlate with the clinical results. Twelve (19%) knees showed a patella baja (Caton ratio <0.6) at follow-up, which correlated with patients immobilized postoperatively by a cylinder cast (P=.04). A valgus alignment at consolidation between 8 degrees and 15 degrees, good muscle strength, and male gender correlated with better results (P<.05). Survivorship analysis, considering an unsatisfactory result or revision to TKR as the endpoint, was 96% at 5 years, 88% at 7 years, 78% at 10 years, and 57% at 15 years. High tibial osteotomy provides symptomatic relief for approximately 10 years, but is unlikely to provide permanent relief.     

The inwardly pointing knee. An unrecognized problem of external rotational malalignment

Twelve patients with inwardly pointing knees had chronic knee pain and disability suggestive of patellofemoral subluxation. None had responded well to conservative measures or surgical correction at the level of the soft tissues. Their pattern of limb alignment was studied roentgenographically and was found to differ significantly from the control group of 49 healthy young adults. The deformities primarily related to the tibia were external tibial torsion, excess varus angulation of the tibial plateau, and varus knees. Angulation of the femoral condyles was normal and femoral anteversion did not appear to contribute significantly to the deformity. Surgery in seven cases (nine knees) was by derotation valgus Maquet osteotomy of the tibia and lateral release realignment of the patellae. Outcome assessments after a three-year follow-up period (five knees) were excellent. Early results on the remaining cases were satisfactory.     

Medical and lateral gonarthrosis treated with high tibial osteotomy. A prospective study

A prospective series comprising 52 knees in 48 patients suffering from medial or lateral unicompartmental gonarthrosis and treated by means of high tibial osteotomy shows, by comparing mechanical axis (MA) 0 degrees corrected knees, how important is the overcorrection of the MA into valgus in medial osteoarthritis. The clinical results were significantly correlated to overcorrection, the results 2 years postoperatively being better than those obtained at a follow-up 1 year after the operation. Of the results, 82% were good within a limit of +/- 3 degrees after 2 years, while only 77% were correspondingly good 1 year postoperatively. In lateral gonarthrosis overcorrection was not as good, but there was a mean overcorrection of +2 degrees, and with respect to this overcorrection, the results were quite acceptable. The results were directly correlated to the opening up of the joint space affected (80%) and diminution or disappearance of subluxation, 1/3 being 0 degrees preoperatively, 1/2 postoperatively in medial gonarthrosis. In lateral gonarthrosis, subluxation was increased, with 2/3 being 0 degrees preoperatively, 1/3 being 0 degrees postoperatively. The extension deficit in varus knees significantly diminished after valgus osteotomy; the change in valgus knees was also evident but not significant. The mean value of extension deficit was below 5 degrees in all cases at the 2 years' follow-up examination. However, 95% of all patients showed good or fair results after a follow-up period of 2 years.     

High tibial osteotomy for osteoarthritis of the knee: a changing concept.

High tibial osteotomy is most successful in patients with osteoarthritis with mild varus deformity which is not associated with subluxation of flexion contracture. Success in the valgus knee is limited. If tibial osteotomy is indicated, undercorrection is undesirable in the varus knee while overcorrection is undesirable in the valgus knee.     

Medial and lateral gonarthrosis treated with high tibial osteotomy

Summary A prospective series comprising 52 knees in 48 patients suffering from medial or lateral unicompartmental gonarthrosis and treated by means of high tibial osteotomy shows, by comparing mechanical axis (MA) 0° corrected knees, how important is the overcorrection of the MA into valgus in medial osteoarthritis. The clinical results were significantly correlated to overcorrection, the results 2 years post-operatively being better than those obtained at a follow-up 1 year after the operation. Of the results, 82% were good within a limit of ± 3° after 2 years, while only 77% were correspondingly good 1 year postoperatively. In lateral gonarthrosis overcorrection was not as good, but there was a mean overcorrection of + 2°, and with respect to this overcorrection, the results were quite acceptable. The results were directly correlated to the opening up of the joint space affected (80%) and diminution or disappearance of subluxation, 1/3 being 0° preoperatively, 1/2 postoperatively in medial gonarthrosis. In lateral gonarthrosis, subluxation was increased, with 2/3 being 0° preoperatively, 1/3 being 0° postoperatively. The extension deficit in varus knees significantly diminished after valgus osteotomy; the change in valgus knees was also evident but not significant. The mean value of extension deficit was below 5° in all cases at the 2 years¹ follow-up examination. However, 95% of all patients showed good or fair results after a follow-up period of 2 years.     

High tibial osteotomy. Use of an osteotomy jig, rigid fixation, and early motion versus conventional surgical technique and cast immobilization

High tibial osteotomy (HTO) using conventional surgical technique and cast immobilization was compared to HTO using an osteotomy jig, rigid internal fixation, and early motion. Fifteen patients (19 knees) had conventional HTO. The mean preoperative femoral-tibial angle was 2.5 degrees of varus, and the mean postoperative angle was 6.5 degrees of valgus. Two knees were undercorrected and eight knees (42%) had associated complications. Twenty patients (21 knees) had HTO utilizing the new surgical technique and postoperative management. The mean preoperative femoral-tibial angle was 2.3 degrees varus, and the mean postoperative angle was 7.6 degrees valgus. One knee was undercorrected (less than 4 degrees valgus) and one knee (5%) had an intraoperative intraarticular fracture. High tibial osteotomy with an osteotomy jig to provide accurate correction, and rigid internal fixation to allow early motion, is an attractive alternative to conventional HTO.     

Knee Instability Before and After High Tibial Osteotomy

Knee joints were examined by three-point measurement (Edholm et al. 1976, 1977). the instability in arthrotic joints did not differ significantly from that in normal knees, but the varus/valgus deviation as measured by the three-point technique differed significantly from that in normal knees. After high tibial osteotomy for varus malalignment the instability increased significantly. An increase of more than 2° was associated with significantly poorer subjective results of operation. the findings indicate that shortening of the lateral stabilizing structures of the knee joint should be carried out in connection with high tibial osteotomy for varus malalignment. No upper limit of preoperative instability consistent with a good result of operation was established.     

Double-elevating osteotomy for late-presenting infantile Blount's disease: the importance of concomitant lateral epiphysiodesis

We reviewed 34 knees in 24 children after a double-elevating osteotomy for late-presenting infantile Blount's disease. The mean age of patients was 9.1 years (7 to 13.5). All knees were in Langenski?ld stages IV to VI. The operative technique corrected the depression of the medial joint line by an elevating osteotomy, and the remaining tibial varus and internal torsion by an osteotomy just below the apophysis. In the more recent patients (19 knees), a proximal lateral tibial epiphysiodesis was performed at the same time. The mean pre-operative angle of depression of the medial tibial plateau of 49 degrees (40 degrees to 60 degrees ) was corrected to a mean of 26 degrees (20 degrees to 30 degrees ), which was maintained at follow-up. The femoral deformity was too small to warrant femoral osteotomy in any of our patients. The mean pre-operative mechanical varus of 30.6 degrees (14 degrees to 66 degrees ) was corrected to 0 degrees to 5 degrees of mechanical valgus in 29 knees. In five knees, there was an undercorrection of 2 degrees to 5 degrees of mechanical varus. At follow-up a further eight knees, in which lateral epiphysiodesis was delayed beyond five months, developed recurrent tibial varus associated with fusion of the medial proximal tibial physis.     

The Coronal Plane High Tibial Osteotomy. Part 1: A Clinical and Radiographic Analysis of Intermediate Term Outcomes

The coronal plane high tibial osteotomy is a novel technique that is used to treat tibiofemoral malalignment. The authors hypothesize that the coronal plane high tibial osteotomy is (1) efficacious in treating both varus and valgus tibiofemoral malalignment; (2) does not alter the slope of the proximal tibia; and (3) does not alter the relationship between the patella and tibial tubercle. A retrospective review of 25 patients with tibiofemoral malalignment (19 varus/6 valgus) treated with a coronal plane osteotomy with a minimum of 2-year follow-up was performed. A Kaplan–Meyer survival curve was performed using knee arthroplasty and a Hospital for Special Surgery (HSS) knee score <70 as failure criteria. The Insall–Salvati ratio and the proximal tibial slope were measured. A p value of 0.05 was considered significant. At 60-month follow-up, knees with initial varus malalignment had an 84% survival rate using both knee arthroplasty and the HSS score as endpoints. Knees with initial valgus malalignment had an 84 and 60% survival rate using knee arthroplasty and the HSS score as endpoints, respectively. There was no statistically significant change in the Insall–Salvati ratio and proximal tibial slope after coronal plane osteotomy. The coronal plane osteotomy is efficacious in treating varus and valgus tibiofemoral malalignment and does not alter the patellar–tibial tubercle relationship or the posterior tibial slope [case series (level of evidence: IV)].     

Valgus Ankle Degenerative Arthritis with an Isolated Deltoid Insufficiency and Tibial Varus: A Case Report

We report a case of valgus ankle degenerative arthritis due to chronic isolated deltoid insufficiency combined with tibial varus that was treated successfully with ankle joint preserving surgery. A 63-year-old male complained of right lateral ankle pain with 10 minutes of maximal pain-free walking time. The assessed American Orthopaedic Foot and Ankle ankle-hindfoot scale score was 33 points. The ankle joint showed 18° of valgus deformity with 6° of tibia varus. Medial displacement calcaneal osteotomy, supramalleolar open wedge osteotomy, and deltoid ligament imbrication were performed. At the 2-year follow-up examination, the ankle joint showed 10° of valgus and the tibial plafond showed flattening. The hindfoot showed 7° of valgus. He could run for 2 hours on the treadmill without pain. The American Orthopaedic Foot and Ankle ankle-hindfoot scale score was 90 points. In conclusion, valgus ankle degenerative arthritis with isolated deltoid insufficiency and tibial varus could be treated successfully with realignment using a double osteotomy and additional deltoid imbrication.     

Recurrent varus angulation after high tibial osteotomy: an anatomic analysis

Recurrent varus deformity and an associated lateral instability are a common and perplexing concern after high tibial osteotomy. An anatomic study using fresh cadaver specimens was done to delineate the cause of this complication. A closing wedge osteotomy was done on four cadaveric knees, which then were subjected to a small varus load to simulate the adduction moment experienced by the knee during normal gait. The osteotomy was progressively closed in 5 degree increments and the angular alignment of the knee was measured with each incremental change. Experimental results identified postosteotomy angular corrections to be 50%, or less, of the predicted value. As the osteotomy was closed progressively the lateral joint space increased concomitantly, creating an effective lateral instability and negating much of the angular correction afforded by the osteotomy. At osteotomy angles greater than 10 degrees the lateral collateral ligament was rendered nonfunctional with the lateral capsule and the anterior cruciate ligament assuming the primary function of stabilizing the lateral side of the knee. As commonly done, a closing wedge valgus tibial osteotomy does not alter the lateral collateral tension, which allows the knee to swing back toward native alignment when subjected to a varus load.     

Long-term results of valgus tibial osteotomy

Valgus tibial osteotomy is a well-recognized procedure for medial compartment arthritis of the knee. The femorotibial angle must be adequately realigned; most unsatisfactory outcomes result from undercorrection. This study of 27 patients (38 knees) with a valgus tibial osteotomy for unicompartmental arthritis of the knee emphasizes the importance of correct alignment. Alignment outside the acceptable range did accelerate deterioration in these patients, followed for an average of 53 months. In 25 of the 38 knees (66%) results were good to excellent. An alignment of 6 degrees or more of valgus produced an excellent to good result in 21 of 23 knees (91%). Alignment of less than 6 degrees of valgus yielded excellent to good results in 4 of 15 knees (27%). Although at the end of one year, 31 of the 38 knees were rated as excellent to good, these knees progressively deteriorated. The knees in 6 degrees or more of valgus seldom deteriorated while those in less than 6 degrees of valgus deteriorated more frequently. A valgus tibial osteotomy is an excellent procedure provided the tibiofemoral angle is realigned to 6 degrees or more of valgus.     

Total knee arthroplasty after varus osteotomy of the distal part of the femur

BACKGROUND: There is little information in the literature regarding the outcome of total knee arthroplasty following distal femoral varus osteotomy. The purpose of the present study was to evaluate the intermediate-term results of total knee arthroplasty following distal femoral varus osteotomy. METHODS: The study group consisted of nine consecutive patients (eleven knees) who had had a total knee arthroplasty following varus osteotomy of the distal part of the femur. The average age of the patients was forty-four years (range, fifteen to seventy years) at the time of the arthroplasty. The results were evaluated with use of the Knee Society score preoperatively and after a mean duration of follow-up of 5.1 years. Radiographs made preoperatively and at the time of follow-up were evaluated for alignment in the coronal plane. RESULTS: The mean Knee Society knee score was 35 points before the arthroplasty and 84 points after the arthroplasty. The mean Knee Society function score was 49 points before the arthroplasty and 68 points after the arthroplasty. The mean interval between the femoral osteotomy and the total knee replacement was fourteen years (range, two to thirty-two years). A constrained prosthesis was required in five of the eleven knees. Two knees had an excellent result, five had a good result, and four had a fair result. The mean arc of motion improved from 81.8 degrees to 105.9 degrees. The mean radiographic alignment was 3.6 degrees of valgus (range, 7 degrees of varus to 18 degrees of valgus) before the arthroplasty and 3.3 degrees of valgus (range, 1 degrees of valgus to 6 degrees of valgus) at the time of the latest follow-up. There were no infections or wound complications. CONCLUSION: Total knee arthroplasty following distal femoral varus osteotomy decreases pain and improves knee function, but the procedure is technically demanding and is associated with inferior results when compared with those of primary arthroplasty performed in a patient without a prior femoral osteotomy. In the present series, the use of an intramedullary femoral alignment guide increased the tendency to place the femoral component in relative varus angulation (that is, in <5 degrees of valgus). We recommend checking the alignment of the femoral component with an extramedullary guide in knees that have had a previous distal femoral varus osteotomy.     

The short-term outcome of surgical treatment for painful varus arthritis in association with chronic ACL deficiency

A review of patients with anterior cruciate ligament (ACL) insufficiency, symptomatic medial compartment osteoarthritis, and varus malalignment of the knee was performed. Twenty-six patients met the inclusion criteria. Twelve patients were treated with a valgus closing-wedge high tibial osteotomy (group 1). Fourteen patients were treated with a valgus closing-wedge high tibial osteotomy combined with arthroscopic ACL reconstruction (group 2). Twenty-five patients were available for follow-up at a minimum of 2 years. For group 1 patients, high tibial osteotomy alone had no effect on the Lachman test or pivot shift phenomena. For group 2 patients, combined high tibial osteotomy/ACL reconstruction resulted in a grade 1 Lachman test in 11 of 13 patients, and a negative pivot shift in 12 of 13 patients. No deficits in range of motion were noted in either group. Prior to surgery, 14 (56%) patients participated in recreational sports; 23 (92%) patients were able to participate in recreational sports at follow-up. Radiographs demonstrated osteoarthritic progression in group 1 and 2 patients (P<.05). The results of this study suggest that high tibial osteotomy alone and combined high tibial osteotomy/ACL reconstructions are effective in the surgical treatment of varus, ACL-deficient knees with symptomatic medial compartment arthritis; however, good or excellent results were more often seen after the combined procedure.     

Optimizing femorotibial alignment in high tibial osteotomy.

OBJECTIVE: To study factors that affect femorotibial (F-T) alignment after valgus closing wedge tibial osteotomy. STUDY DESIGN: A review of standardized standing radiographs. Femorotibial alignment was measured 1 year postoperatively for over- and under-correction. Changes in F-T alignment and in tibial plateau angle were measured. SETTING: An urban hospital and orthopedic clinic. PATIENTS: Eighty-two patients with osteoarthritis and varus femorotibial alignment underwent valgus closing wedge tibial osteotomy. Patients having a diagnosis of inflammatory arthritis or a prior osteotomy about the knee were excluded. RESULTS: A 1 degree wedge removed from the tibia resulted in an average correction F-T alignment of 1.2 degrees. A knee that had increased valgus orientation of the distal femur had a greater degree of correction, averaging 1.46 degrees in F-T alignment per degree of tibial wedge. This resulted in excessive postoperative valgus alignment for some patients who had increased valgus tilt of the distal femur. Optimal F-T alignment of 6 degrees to 14 degrees valgus occurred when the postoperative tibial inclination was 4 degrees to 8 degrees of valgus. CONCLUSIONS: There was a trend for knees with increased valgus orientation of the distal femur to have greater correction in F-T alignment after tibial osteotomy, likely because of a greater opening up of the medial joint space during stance. Surgeons need to account for this in their preoperative planning.     

Total knee arthroplasty for profound varus deformity: technique and radiological results in 173 knees with varus of more than 20 degrees

One hundred seventy-three knees in 117 patients with varus deformity exceeding 20 degrees were prospectively evaluated. Using selective posteromedial release, reduction osteotomy of posteromedial tibial flare, and extra-articular tibial osteotomy, with the preservation of medial collateral ligament integrity, mean tibiofemoral angle of 22.7 degrees varus preoperatively (range, 15 degrees-62 degrees) was corrected to 5.3 degrees valgus (range, 2 degrees-9 degrees) postoperatively. Eighty-six percent of the knees were in 4 degrees to 10 degrees valgus postoperatively. Mean Knee Society score improved from 22.8 (range, 0-64) to 91.1 (range, 52-99), and function score from 22.8 (range, 0-64) to 72.1 (range, 5-100) at 2.6 years (range, 2-9 years). Mean femoral component valgus was 95.5 degrees (range, 92 degrees-98 degrees), and mean tibial component valgus was 89.8 degrees (range, 86 degrees-94 degrees). Of 30 grafts for posteromedial tibial defects, 28 were successfully incorporated. No patient reported significant instability. Three knees (1.7%) showed tibial component loosening with recurrence of deformity. Correction of severe varus deformity by the technique reported can successfully restore alignment, pain-free motion, and stability.     

Intermediate follow-up of high tibial osteotomy: a comparison of two techniques

All high tibial osteotomies (HTOs) performed in the Royal Bournemouth Hospital from June 1987 to February 1995 were retrospectively analyzed looking at the preoperative and postoperative radiographs, preoperative and postoperative range of motion (ROM), alignment, and knee scores. Patient perception was also recorded. In all there were 68 high tibial osteotomies (HTOs), of which 40 were performed by Maquet's dome method and 28 were done by closing wedge osteotomy. Average follow up was 8.6 years (range: 5.2 to 13 years) and 16 (23.5%) cases went on to have total knee arthroplasty after an average interval of 3.7 years. The results of the two methods are compared. Average preoperative HTO alignment was a varus of 4.72 degrees and average postoperative HTO alignment was a valgus of 1.48 degrees. The average radiological grade of osteoarthritis and compartments affected was comparable in the two groups. Overall 35 (51.5%) patients were dissatisfied with their results. A larger percentage of people (57.5%) who had a Maquet's dome osteotomy were unhappy with their operation as compared to 42.9% of people who were unhappy following a closing wedge osteotomy. There was consistent undercorrection after dome osteotomy, with an average alignment of a varus of 1.45 degrees compared to a valgus of 5.67 degrees after a closing wedge procedure. The preoperative subluxation was greater in the patients with a relatively poor result, 3.86 mm compared to 2.03 mm in those with a good result. It is felt that the rather poor results following osteotomy in this series was due to insufficient correction obtained and the advanced stage of osteoarthritis resulting in subluxation. In this series the correction obtained with closing wedge method was better than with the dome method, although it was inadequate with both methods. Although the wedges appeared to do better than the domes, this was not statistically significant. Overall, there was no significant correlation of our results with post osteotomy alignment. Preoperative lateral tibial subluxation was, however, a poor prognosticator of results.     

Decrease of osteosclerosis in subchondral bone of medial compartmental osteoarthritic knee seven to nineteen years after high tibial valgus osteotomy

Osteosclerosis of the subchondral bone was measured by densitometer on plain radiographs in 55 medial compartmental osteoarthritic knees of 40 patients who were treated with high tibial valgus osteotomy for correction of varus deformity. The ratio of the osteosclerosis value of the medial side of the knee to that of the lateral side (Medial/Lateral ratio) was calculated and used as a parameter. The Medial/Lateral ratio of osteosclerosis decreased rapidly within three years after osteotomy at the reference points of the femur and the tibia. Even 7 to 19 years after osteotomy, a decrease of the ratio was noted in 16 knees with a standing femorotibial angle (FTA) less than 168 degrees (12 degrees of anatomical valgus angulation). This was interpreted to mean that osteosclerosis of the medial condyle decreased compared with that of the lateral condyle after overcorrection of varus deformity. In the cases of more than 7 years after high tibial osteotomy, a positive straight regression line was drawn by calculation between Medial/Lateral ratio and postoperative limb alignment expressed by standing femorotibial angle, with coefficient of correlation (gamma) of 0.295 (p < 0.01).     

Effect of high tibial flexion osteotomy on cartilage pressure and joint kinematics: a biomechanical study in human cadaveric knees

Introduction Valgus high tibial osteotomy is an established treatment for unicompartmental varus osteoarthritis. However, only little is known about the effect of osteotomy in the sagittal plane on biomechanical parameters such as cartilage pressure and joint kinematics. This study investigated the effects of high tibial flexion osteotomy in a human cadaver model.Materials and methods Seven fresh human cadaveric knees underwent an opening wedge osteotomy of the proximal tibia in the sagittal plane. The osteotomy was opened anteriorly, and the tibial slope of the specimen was increased gradually. An isokinetic flexion-extension motion was simulated in a kinematic knee simulator. The contact pressure and topographic pressure distribution in the medial joint space was recorded using an electronic pressure-sensitive film. Simultaneously the motion of the tibial plateau was analyzed three-dimensionally by an ultrasonic tracking system. The traction force to the quadriceps tendon which was applied by the simulator for extension of the joint was continuously measured. The experiments were carried out with intact ligaments and then after successively cutting the posterior and anterior cruciate ligaments.Results The results demonstrate that tibial flexion osteotomy leads to a significant alteration in pressure distribution on the tibial plateau. The tibiofemoral contact area and contact pressure was shifted anteriorly, which led to decompression of the posterior half of the plateau. Moreover, the increase in the slope resulted in a significant anterior and superior translation of the tibial plateau with respect to the femoral condyles. Posterior subluxation of the tibial head after cutting the posterior cruciate ligament was completely neutralized by the osteotomy. The increase in slope resulted in a significant higher quadriceps strength which was necessary for full knee extension.Conclusions We conclude from these results that changes in tibial slope have a strong effect on cartilage pressure and kinematics of the knee. Therapeutically a flexion osteotomy may be used for decompression of the degenerated cartilage in the posterior part of the plateau, for example, after arthroscopic partial posterior meniscectomy. If a valgus osteotomy is combined with a flexion component of the proximal tibia, complex knee pathologies consisting of posteromedial cartilage damage and posterior and posterolateral instability can be addressed in one procedure, which facilitates a quicker rehabilitation of these patients.Winner of the AGA-DonJoy Award 2003