Proximal tibial osteotomy. A critical long-term study of eighty-seven cases

Patellar height and the inclination of the tibial plateau after high tibial osteotomy. The open versus the closed-wedge technique

Our aim was to compare the degree of patellar descent and alteration in angle of the inclination of the tibial plateau in lateral closing-wedge and medial opening-wedge high tibial osteotomy (HTO) in 51 consecutive patients with osteoarthritis of the medial compartment and varus malalignment. Patellar height was measured by the Insall-Salvati (IS) and the Blackburne-Peel (BP) ratios. The tibial inclination was determined by the Moore-Harvey (MH) method. Multivariate linear regression analysis was used to determine the influence of the type of HTO (closing vs opening wedge) on the post-operative patellar height or tibial inclination. The intra- and interobserver variability of these methods was determined before operation and at follow-up at one year. After an opening-wedge HTO the patellar height was significantly more decreased (mean post-operative difference: IS = 0.15; 95% confidence interval (CI) 0.06 to 0.23; BP = 0.11; 95% CI 0.05 to 0.18) compared with a closing-wedge HTO. The angle of tibial inclination differed significantly (mean post-operative difference MH = -6.40 degrees; 95% CI -8.74 to -4.02) between the two HTO techniques, increasing after opening-wedge HTO and decreasing after closing-wedge HTO. There was no clinically-relevant difference in the intra- and interobserver variability of measurements of patellar height either before or after HTO.

High tibial osteotomy for the treatment of unicompartmental arthritis of the knee

Knee axial deformities associated with medial or lateral compartment osteoarthritis can be reliably addressed with high tibial osteotomies. Different surgical techniques can be successfully used for achieving the correction. Whatever the technique used, accurate patient selection and precise surgical procedure are critical to the success of the operation. The authors believe that proximal tibial osteotomy is a valuable procedure to achieve pain relief and to restore knee function in selected patients. Localized knee osteoarthritis of the highly motivated, older, active patient can also be included in the extended indications of the high tibial osteotomy.

Biomechanical stability of high tibial opening wedge osteotomy: internal fixation versus external fixation

PURPOSE

The goal of our study was to evaluate stability of internal fixation with a plate compared to external fixation in an opening wedge high tibial osteotomy model. Significance. To our knowledge, this is the only study to compare internal plate to external fixation in an opening wedge osteotomy model. The design of this cadaver study limits its direct application to clinical practice.

MATERIAL AND METHOD

In each of the six pairs of fresh-frozen human cadaver knees one specimen was randomly assigned to internal plate fixation while the other was stabilized with an external fixation. The osteosynthesis plate incorporated a 12.5mm block that distracted the medial tibial cortices. Each knee was loaded on a mechanical testing machine to 700 N for 10,000 cycles to simulate immediate full weight bearing in a walking individual.

SUMMARY OF RESULTS

The internal plate osteosynthesis provided significantly greater stiffness and smaller loss of correction (1.60mm) than the external fixation (3.22 mm) under cyclic loading condition (P<0.05). For static loading, the mean value of stiffness resulting in failure for the internal plate and external fixation, were respectively, 938 N/mm and 459 N/mm. Load to failure also showed two times greater stiffness in the plate osteosynthesis group. No hardware failure was observed in either construct.

DISCUSSION AND CONCLUSION

Plate fixation was superior to external fixation in maintaining correction. However, progressive adjustment of the distraction with the external fixator allows precise "fine-tuning" during the healing process that is not possible with internal fixation.

Navigated osteotomies around the knee in 170 patients with osteoarthritis secondary to genu varum

The authors used computer navigation to perform osteotomies around the knee. The purpose of this article is to present the authors' surgical technique and to discuss double-level osteotomy of the femur and tibia to avoid altered joint line obliquity in genu varum deformity. The authors conducted two studies. The first study was a cohort study comparing navigated high tibial osteotomies and conventional high tibial osteotomies. The results showed a 96% reproducibility in achieving a mechanical axis of 184 degrees +/- 2 degrees in the navigated group compared to a 71% reproducibility in achieving a mechanical axis of 184 degrees +/- 2 degrees in the conventional osteotomy group (P < .0015). The second study was a prospective study on double-level osteotomy and showed that the preoperative goal of 182 degrees +/- 2 degrees has been achieved in 91% of patients.

The effect of lateral cortex disruption and repair on the stability of the medial opening wedge high tibial osteotomy

BACKGROUND

Medial opening wedge high tibial osteotomy is gaining popularity as a treatment option for medial compartment degenerative disease in the young, active patient. One of the potential technical pitfalls of this procedure is inadvertent disruption of the lateral tibial cortex during distraction at the osteotomy site.

PURPOSE

(1) To investigate the effect of lateral cortex disruption on stability during medial opening wedge high tibial osteotomy and (2) to evaluate 3 different methods of repair of the disrupted lateral cortex.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 50 validated replicate tibias were evaluated in a medial opening wedge high tibial osteotomy model. Specimens were divided into 5 groups: (1) control, or intact lateral cortex (n = 10); (2) disrupted lateral cortex (n = 10); (3) lateral cortex repaired with 1 staple (n = 10); (4) lateral cortex repaired with 2 staples (n = 10); and (5) lateral cortex repaired with a periarticular plate and screws (n = 10). Specimens were placed in compression and torsion under physiologic loads, and stiffness and micromotion were calculated.

RESULTS

Disruption of the lateral cortex resulted in a 58% reduction in axial stiffness and a 68% reduction in torsional stiffness compared to control specimens (P < .05). Disruption of the lateral cortex also resulted in increased micromotion at the osteotomy site. All 3 methods of repair of the lateral cortex restored stiffness and micromotion values to those of the control group (P < .05).

CONCLUSIONS

Instability at the osteotomy site may contribute to the high rate of delayed union or nonunion associated with medial opening wedge high tibial osteotomy. Repair of the lateral tibial cortex by each of these techniques restored stability to the osteotomy site in this replicate tibia model and might be effective in clinical use. However, more studies are needed to further explore the relationship between lateral cortex disruption and patient outcomes in the clinical setting before definitive conclusions can be drawn.

High tibial osteotomy

High tibial osteotomy is effective for managing a variety of knee conditions, including gonarthrosis with varus or valgus malalignment, osteochondritis dissecans, osteonecrosis, posterolateral instability, and chondral resurfacing. The fundamental goals of the procedure are to unload diseased articular surfaces and to correct angular deformity at the tibiofemoral articulation. Although the clinical success of total knee arthroplasty has resulted in fewer high tibial osteotomies being done during the past decade, the procedure remains useful in appropriately selected patients with unicompartmental knee disease. Renewed interest in high tibial osteotomy has occurred for a number of reasons. These include the prevalence of physiologically young active patients presenting with medial compartment osteoarthritis; the advent of new techniques for performing the procedure (ie, improved instrumentation and fixation plates for medial opening wedge osteotomy, dynamic external fixation for medial opening wedge osteotomy, and improved instrumentation for lateral closing wedge osteotomy); and the need to concomitantly correct malalignment when performing chondral resurfacing procedures (ie, autologous chondrocyte transplantation, mosaicplasty, and microfracture).

A 2-year prospective study of patient-relevant outcomes in patients operated on for knee osteoarthritis with tibial osteotomy

BACKGROUND

Tibial osteotomy is a treatment for younger and/or physically active patients suffering from uni-compartmental knee osteoarthritis. The open wedge osteotomy by the hemicallotasis technique includes the use of external fixation. The use of external fixation has several advantages, as early mobilization and the opportunity for optimal correction. However, the hemicallotasis technique has also been described as a cumbersome procedure for the patient. The aim of this study was to prospectively evaluate patient-relevant outcomes during the first 2 post-operative years. Especially the treatment period, during which external fixation was used, was closely monitored.

METHODS

In an uncontrolled study, fifty-eight consecutive patients, 30 men and 28 women (mean age 54 years) were operated on by the hemicallotasis technique were evaluated with the patient-relevant outcome measure Knee injury and Osteoarthritis Outcome Score (KOOS) preoperatively, during the treatment with external fixation, one week after removal of the external fixation, at 6 months, and at one and two years postoperatively.

RESULTS

At the 2-year postoperative follow-up, all subscales of the KOOS were improved (p < 0.001), mostly in pain (41-80 on a 0-100 worst to best scale) and knee-related quality of life (21-61 on a 0-100 worst to best scale), compared to the preoperative status. Significant improvements in pain and other symptoms, function of daily life and quality of life were seen already during the treatment period (mean 98 +/- 18 days) with the external fixation. More demanding functions such as kneeling, squatting, jumping and running, were improved first after extraction of the external fixation device and the pins.

CONCLUSION

Tibial osteotomy by the hemicallotasis technique yields large improvement in self-rated pain, function and quality of life, which persists over two years. Surprisingly, large improvements occurred already during the immediate post-operative period when the external fixation was still used.

Preoperative tibiofemoral angle predicts survival of proximal tibia osteotomy

A prospective group study was done to clarify whether perioperative variables such as preoperative and postoperative tibiofemoral angles influence the survivorship of proximal tibia osteotomy as measured by conversion to arthroplasty and patient dissatisfaction. The results of 93 proximal tibial osteotomies in 82 consecutive patients with medial compartment osteoarthrosis were followed up for a mean of 10.9 years. All data were analyzed by the Kaplan-Meier survivorship method and the multivariate Cox proportional hazards model. Only the preoperative tibiofemoral angle was a predictor of conversion to arthroplasty and patient dissatisfaction. The ideal prognostic cutoff angle was 9 degrees or less varus. Increasing the preoperative varus alignment 1 degrees would result in a 1.2 (95% confidence intervals, 1.02-1.50) times higher risk of conversion to a total knee arthroplasty and a 1.5 (95% confidence intervals, 1.27-1.76) times higher chance of patient dissatisfaction. Factors such as age, gender, body mass index, Ahlback's classification, and postoperative tibiofemoral angle were not significant. We think that proximal tibial osteotomy should be considered for patients with medial compartment osteoarthrosis and a preoperative varus alignment of 9 degrees or less, whereas arthroplasty is a more suitable alternative for patients with preoperative varus alignment greater than 9 degrees.

Osteotomy for treating knee osteoarthritis

BACKGROUND

Patients with unicompartmental osteoarthritis of the knee can be treated with a correction osteotomy. The goal of the correction osteotomy is to transfer the load bearing from the pathologic to the normal compartment of the knee. A successful outcome of the osteotomy relies on proper patient selection, stage of osteoarthritis, achievement and maintenance of adequate operative correction.

OBJECTIVES

To assess the effectiveness and safety of an osteotomy for treating osteoarthritis of the knee.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE (Current contents, Health STAR) were searched up until October 2002 for controlled clinical trials. The reference lists of publications in the identified trials were also screened.

SELECTION CRITERIA

Extracted studies were included in the final analysis if they met the pre-defined inclusion criteria: 1) a randomised controlled clinical trial or a controlled clinical trial 2) all patients had unicompartmental osteoarthritis of the medial or lateral compartment of the knee 3) the intervention in one of the studied groups was a high tibial osteotomy or a distal femoral osteotomy.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected the trials, assessed the methodological quality using a validated tool and extracted the data. The planned analysis was to pool the results where appropriate, however, due the heterogeneity of the studies, pooling of the outcome measures was not possible. Results are described for each study and presented as a best evidence synthesis.

MAIN RESULTS

Following the search strategy and applications of selection criteria, eleven studies were included in this review. All the studies concerned a valgus high tibial osteotomy (HTO) for medial compartment osteoarthritis of the knee. Four studies compared two techniques of HTO. One study compared HTO alone versus HTO with additional treatment. Four studies compared within the same type of HTO, different per-operative conditions (two studies) or two different types of post-operative treatment (two studies). Two studies compared HTO with unicompartmental joint replacement. No study compared an osteotomy with conservative treatment. Most studies showed improvement of the patient (less pain and improvement of function scores) after osteotomy surgery, but in the majority of the studies there was no significant difference with other operative treatment (other technique of HTO/ unicompartmental joint replacement). Overall, the methodological quality was low.

AUTHORS' CONCLUSIONS

Based on 11 studies, of which 6 were high quality, we conclude that there is silver level evidence that valgus HTO improves knee function and reduces pain. There is no evidence whether an osteotomy is more effective than conservative treatment and the results so far do not justify a conclusion about effectiveness of specific surgical techniques.

Open-wedge high tibial osteotomy: a technical trick to avoid loss of reduction of the opposite cortex

High tibial osteotomies for the treatment of gonarthrosis in young and active patients are well-accepted and frequently performed procedures. Several techniques are described to achieve good axial alignment with enough stability for early motion, but they come along with a considerable number of complications, such as insufficient or excessive axial correction, loss of reduction, delayed union, and pseudoarthrosis. We present a case of early loss of reduction in a medial opening-wedge high tibial osteotomy and a simple technical trick to avoid and treat this potential complication.

Osteotomies around the Knee for the Young Athlete with Osteoarthritis

There exists a growing number of patients with osteoarthritis who are difficult to classify and treat due to their younger age and higher activity level. Many of these athletic patients have sustained meniscal injury, previous meniscectomy, or articular cartilage injury, and may develop osteoarthritic symptoms. Fewer patients present with underlying malalignment or ligamentous instability and increasing arthrosis. Ostoeomies about the knee have been shown to unload isolated medial and lateral compartment osteoarthritis and decrease symptoms in the older adult patient who has been considered too young for total knee replacement. We describe a treatment approach to the younger athlete with isolated unicompartmental osteoarthritis.

Anterior cruciate reconstruction combined with valgus upper tibial osteotomy: 12 years follow-up

A retrospective review of 29 patients (30 knees) was carried out who had previously undergone a single-stage combined ACL reconstruction with valgus upper tibial osteotomy for chronic ACL rupture coupled with early medial tibio-femoral arthritis. Of the 30 knees, 19 (63%) had had a previous medial meniscectomy. Major complications occurred in two knees resulting in stiffness. At a mean of 12 years follow-up (6-16 years) only five knees (17%) had progressed one arthritis grade. Fourteen patients (47%) returned to intensive sports, and a further 11 (37%) played moderate sports. The mean difference in anterior tibial translation with the opposite normal knee was 3 mm at review. It was concluded that the combined operation has a low morbidity, controls anterior laxity, allows many patients to return to sports, and does not result in a rapid progression of osteoarthritis.

Fifteen to twenty-eight years' follow-up results of high tibial valgus osteotomy for osteoarthritic knee

A long-term follow-up study was performed on 75 knees of 53 patients after high tibial valgus osteotomy. The earlier results have previously been reported. There were 15 knees in 11 men and 60 knees in 42 women. The follow-up period ranged from 15 to 28 years with a mean of 19 +/- 3 years. The age at osteotomy ranged from 46 to 73 years with a mean of 59.6 +/- 6.7 years. The diagnosis was medial compartmental osteoarthritis (OA) in 68 knees (46 patients) and spontaneous osteonecrosis of the medial femoral condyle in 7 knees (7 patients). Valgus osteotomy was performed above the tibial tuberosity, with removal of a laterally based wedge in all cases, aiming for anatomical valgus angulation of 10 degrees . The American Knee Society Score showed a Knee Score of 37 +/- 20 and a Function Score of 38 +/- 16 preoperatively and 87 +/- 13 and 80 +/- 19 at the final 15 to 28 years' follow-up. The femoro-tibial angle in standing was 186 +/- 6.5 degrees (6 degrees of anatomical varus angulation) before and 171 +/- 7.5 degrees (9 degrees of anatomical valgus angulation) at final follow-up (p < 0.0001), with no apparent loss of limb alignment.

Effects of rotation on measurement of lower limb alignment for knee osteotomy

The purposes of this study were to clarify the effects of rotation on two-dimensional measurement of lower limb alignment for knee osteotomy using a three-dimensional method and to determine whether this 3-D simulation method could help with planning of knee osteotomy. We developed computer software to calculate femorotibial angle (FTA) and hip-knee-ankle angle (HKA) and simulate knee osteotomy from a CT-based 3-D bone model of the lower limb. Lower limb rotation on anteroposterior long-standing radiographs was measured by superimposing the 3-D bone models. Changes in alignment with limb rotation were calculated using the software. FTA after virtual closed-wedged osteotomy was measured for a hypothetical case of a rotation error of the osteotomy plane in reattaching the proximal cutting surface to the distal cutting surface. For 31 varus knees in 20 patients with medial compartment arthritis, the mean rotation angle, relative to the epicondylar axis, with variable limb position was 7.4 +/- 3.9 degrees of internal rotation (mean +/- SD), ranging from 8 degrees of external rotation to 14 degrees of internal rotation; the mean changes in FTA and HKA were 3.5 +/- 2.2 degrees (range, 0.4-8.6) and 1.6 +/- 1.3 degrees (range, 0.2-4.9), respectively. The FTA "flexion angle" (lateral view alignment from neutral AP) and the absolute HKA "flexion angle" correlated with the change in FTA and HKA with limb rotation, respectively (FTA, R = 0.999; HKA, R = 0.993). The mean change in FTA after virtual closed-wedged osteotomy was 3.2 degrees for internal and external 10 degrees rotation errors in reattaching the osteotomy plane. Rotation may affect measurement of lower limb alignment for knee osteotomy, and 3-D methods are preferable for surgical planning.

Effect of high tibial flexion osteotomy on cartilage pressure and joint kinematics: a biomechanical study in human cadaveric knees. Winner of the AGA-DonJoy Award 2004

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.

The role of osteotomy 2003: defining the niche

Although the use of traditional high tibial osteotomy in the unicompartmental osteoarthritic knee has declined due to high failure rates at 10 years, results that are generally poorer than total and unicompartmental arthroplasty, and difficulties with conversion to TKR, a potential role for osteotomy still exists. As long-term data becomes available to support or refute the renewed enthusiasm in the more modern techniques and applications, the indications for osteotomies about the knee will become better defined.

[Stability, bone healing and loss of correction after valgus realignment of the tibial head. A roentgen stereometry analysis]

In high tibial closing-wedge osteotomies (HTO), closure of an osteotomy gap after resection of a bony wedge can be associated with a fissure of the medial cortex of the tibial head (MCT). The effect of a broken MCT on the recurrence of varus deformity is disputed. In this study, serial roentgen stereometric analysis (RSA) was used to determine the fixation stability of a rigid internal "L" plate after HTO. Full weight lower limb radiographs were used to determine the sagittal alignment in patients with varying degrees of varus malalignment and correction over time. Forty-two patients with varus gonarthrosis stage I-III (Ahlback) were treated with HTO and internal fixation with an L-shaped rigid plate. Patients were followed by serial RSA, conventional radiographs, and clinical evaluation (Hospital of Special Surgery score) over a 12-month period. In 19 of 42 successive patients, an average wedge size of 6.9 degrees was resected leaving the MCT intact (group 1). In 23 of 42 of patients, the MCT was unintentionally fissured during surgery when an average 10.3 degrees -wedge was resected (group 2). In group 2, RSA revealed a fivefold increase in lateral displacement of the distal tibial segment within 3 weeks after HTO. Twelve weeks after HTO, translations between tibial segments were below the accuracy of the RSA setup in the majority of patients. Group 1 patients demonstrated a higher initial fixation stability, less occurrence of varus deformity, and a higher HSS score compared to patients with larger wedge sizes and frequent fracture of the MCT (group 2). Before bone healing is achieved, the integrity of the MCT plays a crucial role for the clinical and radiological outcome after HTO.

[Possibilities of computer-assisted navitation in knee para-articular osteotomies]

Osteotomies in the knee region for incipient osteoarthritis in active patients have become increasingly popular in recent years. A computer-guided navigation system should help increase the surgeon's accuracy and lower the risk of intraoperative complications for this technically demanding type of surgery. Furthermore, computer navigation might be a powerful research and educational tool. The technical principles and the clinical implications of this system for knee osteotomies are described in the following article.

[Imaging and preoperative planning of osteotomy of tibial head osteotomy]

Valgus-producing osteotomy of the proximal tibia is a well-established treatment for medial femorotibial osteoarthritis in the varus knee. The ideal patient is active, under 55 years of age, has a stable varus deformity of less than 10 degrees, a good bone stock, and an osteoarthritis stage that is restricted to the medial compartment of the knee. Coventry reported a failure rate in proximal tibial osteotomy to be significantly higher when the postoperative alignment was less than 8 degrees of anatomical valgus. Hernigou noted better clinical long-term results in cases with a precise correction of malalignment. There are different preoperative planning methods varying between simple estimates of correction angles and specific radiographic planning tools. The reproducibility of operative outcome with regard to a predictable anatomic alignment and functional recovery must have high priority. This chapter deals with different preoperative planning methods to improve the reliability of surgical results after tibial osteotomy.

[Closing wedge osteotomy of the tibial head in treatment of single compartment arthrosis]

Closing wedge high tibial osteotomy is an efficient method for the treatment of medial osteoarthritis of the knee. Prerequisites of successful surgery are proper indication and planning as well as the understanding of biomechanics and pathophysiology. The technique of osteotomy to choose (opening or closing wedge) depends on the type of malalignment and on additional pathologies. The surgical technique demands high precision to realize the planned correction and to avoid complications. Implants with angular stability provide advantages compared to traditional implants. Correct indication and surgical technique results in a desirable follow-up, which often lasts for at least 10 years. The effect on the prognosis of the young patient with cartilage damage is still unclear.

Patella kinematics and patello-femoral contact areas in patients with genu varum and mild osteoarthritis

BACKGROUND

Patients with genu varum of the knee and moderate to severe osteoarthritis often suffer from additional symptoms of the patello-femoral joint. These patients have a poor prognosis following high tibial osteotomy. It is unclear whether varus knees with only mild femoro-tibial osteoarthritis are also associated with alterations of patella biomechanics, and affect the prognosis of intended high tibial osteotomy.

METHODS

Fifteen patients with genu varum and mild osteoarthritis and 15 healthy volunteers were assessed in an open MRI-scanner. 3D-GRE sequences of the knee were obtained in 0 degrees, 30 degrees and 90 degrees with and without activity of the extensor muscles. After segmentation of patella, femur, tibia and the adjacent cartilage, a patella-based local coordinate system was established. Femoral and tibial reference points allowed definition of the spatial position of the patella. Contact areas were defined by intersection of opposing cartilage volumes.

FINDINGS

No significant differences in patella kinematics and patello-femoral contact areas could be found (P > 0.05) between varus knees with mild osteoarthritis and healthy knees either at different flexion angles or under extending muscle activity.

INTERPRETATION

In knees with genu varum and mild medial osteoarthritis we could detect no alterations in patello-femoral kinematics. Since the alterations of patients with genu varum and mild osteoarthritis are restricted to the medial femoro-tibial joint high tibial osteotomy might be successful.

Proximal tibial osteotomy: where did you go?

The prevalence of knee osteotomy seems to have diminished. Better total knee arthroplasty (TKA) results, greater survival, increased use of unicompartmental arthroplasty, and decreased surgeon confidence for osteotomy are likely causes. However, continued use of knee osteotomy is encouraged by this author. TKAs are not perfect. Furthermore, there is limited long-term durability data for younger, active patients. At 40 to 60 years of age at the time of surgery, some patients will need prosthetic replacements that must last up to 40 to 60 years. A case is made for performing an osteotomy earlier rather than later. Regarding TKA after proximal tibial osteotomy, the difficulty and inappropriateness of the standard comparisons are clear. Comparison of a virgin primary knee at one point in time, with a patient whose situation led to osteotomy surgery 5 to >10 years earlier is not a matched comparison. It is proposed that future biologic resurfacing, together with computer-and even robotic-methods, as well as other advances in biology and technology, will combine to resurrect the performance of knee osteotomies.

Minimally invasive unicondylar knee arthroplasty for the treatment of unicompartmental osteoarthritis: an outpatient arthritic bypass procedure

This review summarizes past studies examining the progression of osteoarthritis (OA) of the knee that have led to the conclusion that the disease is slow, progressive, and typically limited to one tibiofemoral compartment. Treatments such as unicondylar knee arthroplasty (UKA) that address the single diseased compartment, preserving bone and soft tissue, seem appropriate. The senior author's minimally invasive surgical technique for performing UKA also is described.

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.

Total knee arthroplasty following proximal tibial osteotomy: risk factors for failure

BACKGROUND

The results of proximal tibial osteotomy are known to deteriorate over time, with the majority of patients eventually requiring total knee arthroplasty. The outcome of total knee arthroplasty in patients who have had a proximal tibial osteotomy, compared with that of routine primary total knee arthroplasty, remains controversial. The purpose of the present study was to evaluate the long-term clinical and radiographic outcome of total knee arthroplasty in patients who had undergone a previous proximal tibial osteotomy and to identify the risk factors that may result in an inferior outcome.

METHODS

Between 1980 and 1990, 166 cemented condylar total knee prostheses were implanted in 118 patients who had had a previous proximal tibial osteotomy for the treatment of osteoarthritis. The study group included seventy-seven men and forty-one women who had a mean age of 69.1 years at the time of knee arthroplasty. The average interval between the osteotomy and the total knee arthroplasty was 8.6 years. The average duration of clinical follow-up was 15.1 years, and the average duration of radiographic follow-up was 9.2 years.

RESULTS

The mean Knee Society pain score improved from 34.5 to 82.9 points, and the mean function score improved from 44.6 to 88.1 points. There was also a substantial improvement in the mean arc of motion. Thirteen knees (8%) were revised at a mean of 5.9 years. At the time of the final follow-up, progressive complete radiolucent lines indicating a loose prosthesis were present around seventeen tibial components and seven femoral components.

CONCLUSIONS

There was a very high rate of radiographic evidence of loosening. Male gender, increased weight, young age at the time of total knee arthroplasty, coronal laxity, and preoperative limb malalignment were identified as risk factors for early failure. Despite these findings, total knee arthroplasty can provide reliable and durable pain relief and improvement in function for patients who have had a previous proximal tibial osteotomy.

LEVEL OF EVIDENCE

Prognostic study. Level II-1 (retrospective study). See Instructions to Authors for a complete description of levels of evidence.

A new computer-assisted method for measuring the tibio-femoral angle in patients with osteoarthritis of the knee

OBJECTIVE

The purpose of this study was to evaluate the inter- and intraobserver variability in measuring the tibio-femoral angle using our new computer-assisted method, and to compare it with a conventional manual method.

METHODS

Radiography of all patients of osteoarthritis of the knee in outpatient were performed with standing on both legs, and with conventional antero-posterior weight bearing view of the knee fully extended. Three examiners measured the tibio-femoral angle with the computerized method in 52 subjects with osteoarthritis (73 knees). The tibio-femoral angle was measured using a computer-assisted method in which the observer must visually determine and select eight points on the margins of the femur and tibia on a radiographic image displayed on a computer monitor. The inter- and intraobserver Intra-class correlation (ICC) was analyzed.

RESULTS

The interobserver mean correlation of computer-assisted method was 0.970 with a mean difference of 0.38 degrees (S.D. 1.125 degrees). The intraobserver mean ICC of computer-assisted method was 0.973, with a mean difference of 0.16 degrees (S.D. 1.12 degrees). An analysis of the difference between conventional methods and our new system showed a mean ICC of 0.922, with an intersystem mean difference of 0.295 degrees (S.D. 1.82 degrees).

CONCLUSION

Our computer-assisted method of measuring the tibio-femoral angle was simple, easy, and quick, and should be considered as an alternate method for measurement.

Opening wedge high tibial osteotomy for symptomatic hyperextension-varus thrust

BACKGROUND

The purpose of this study was to assess the functional outcome of opening wedge high tibial osteotomy (HTO) in a young, active group of patients with instability rather than osteoarthritis.

METHODS

The results of 17 opening wedge HTOs in 16 patients with a symptomatic hyperextension-varus thrust were evaluated. Functional results were evaluated according to the activity scoring system of Tegner and Lysholm and using a 5-point visual analogue scale to assess change in knee stability and satisfaction. Radiographs were analyzed to determine changes in femorotibial and mechanical axis alignment, tibial slope, and patellar height.

RESULTS

Patients were followed for a mean of 56 months. All patients had an increase in their activity score postoperatively. Nine patients rated their symptoms as significantly better and seven as somewhat better. All but one were satisfied with the surgery. Femorotibial axis alignment was changed to a mean of 6 degrees valgus, mechanical axis alignment was corrected to a mean of 46% toward the lateral compartment, posterior tibial slope was increased a mean of 8 degrees, and the ratio of patellar height was decreased a mean of 0.17.

CONCLUSION

Opening wedge HTO can produce good functional and radiographic results in selected patients with a symptomatic thrust.

Outcome of osteotomies for the treatment of haemophilic arthropathy of the knee

BACKGROUND AND AIMS

The knee is one of the most commonly affected joints in haemophilic arthropathy leading to stiffness and disability. It is the aim of this study to investigate the outcome of corrective osteotomies around the knee.

PATIENTS AND METHODS

We report on the long-term results of ten osteotomies around the knee for severe haemophilic arthropathy and axial deviation at an average of 7.25+/-1.8 years postoperatively. Seven high tibial (preoperatively 7.2+/-2 degrees varus) and three supracondylar osteotomies (preoperatively 7+/-3 degrees valgus) were performed on seven patients (three of them bilateral).

RESULTS

The clinical score of the Advisory Board of the World Federation of Haemophilia (average 7.4 points preoperatively) remained unchanged in two patients, improved in three patients and deteriorated in five patients. The radiological Pettersson score (average 8.2 points preoperatively) showed a worsening of 2.5 points over the time. Patients reported a subjective improvement for seven osteotomies, with sports activity in three patients, although the range of motion did not change significantly. Total knee arthroplasty was considered to be a failure, i.e. endpoint of follow-up. Six knees were replaced in four patients by total arthroplasty after a mean of 6.6 years.

CONCLUSION

Although survival of osteotomies around the knee in haemophilic arthropathy is lower than in non-haemophilic patients, we think that it is a choice of treatment, which, at least, postpones the indication for total knee arthroplasty in this young patient group.

Unicompartmental tibial hemiarthroplasty: early results of the UniSpacer knee

An intra-articular metallic spacer is evaluated for the treatment of isolated medial compartment OA. It is proposed that this implant can provide axial correction for a varus deformity, eliminate the pseudolaxity of the MCL, improve knee function, maintain ROM, and provide pain relief. One-and 2-year data are presented on 71 UniSpacer Knee System implants that were implanted in 67 patients (four had bilateral surgeries). The mean age and weight of these patients was 54 years and 94 kg (207 lb), respectively. The heaviest patient in the group weighed 168 kg (370 lb). All knees were evaluated using the Knee Society clinical rating system, Lysholm scoring scale, radiographic limb alignment, and ROM. The mean Knee Society knee score improved 169% in the 1-year group and 193% in the 2-year group. The mean Knee Society function score improved 31% and 65%, respectively. The mean Lysholm score improved 88% and 140%, respectively. Five implants (7%) were revised to total knee arthroplasty (TKA) and 10 implants (14%) were revised to another UniSpacer Knee System implant. The early results suggest that an intra-articular metallic spacer is a viable treatment option for OA in the younger patient.

The advantages of circular external fixation used in high tibial osteotomy (average 6 years follow-up)

We evaluated the midterm results of high tibial osteotomy in patients with medial compartment arthritis. This study included 53 patients treated with high tibial osteotomy accompanied by either internal fixation (group A, n=26) or Ilizarov-type external fixator (group B, n=27). Clinical assessment of patients was performed using Hospital of Special Surgery scoring. Radiography was based on orientation angles of the knee (medial proximal tibial angle, lateral distal femoral angle, posterior proximal tibial angle) and mechanic axis alignment test. We used the Insall-Salvati index to determine patellar height. The mean follow-up in group A was 77 months (range 63-118) and that in group B 72 months (range 61-113). The patients of group B demonstrated better results in terms of Hospital of Special Surgery score, alignment of lower extremity, and preventing of progression of arthritis. We believe that normal alignment and orientation of the knee could be precisely established with a circular external fixator, and that some disadvantages such as patella infera, failed correction, and loss of bone in proximal tibia as observed after classic high tibial osteotomy can be avoided. Furthermore, progression of arthritis can be prevented if the mechanical axis passes through the lateral compartment of the knee.

Primary stability of various implants in tibial opening wedge osteotomy: a biomechanical study

High tibial osteotomy (HTO) is an established method for treating varus gonarthrosis. The opening wedge HTO has some advantages over the lateral closed wedge technique. In this biomechanical study various systems of internal fixation of medial HTO were compared using an animal cadaver model (lower leg specimens from 1-year-old female domestic pigs). The first osteotomy (10 degrees ) was carried out and stabilized with a C-plate, an Arthrex spacer plate, or an AO tibial plate with or without bone graft. The resistance to axial stress was tested in a mechanical testing machine. Under lower axial stress (25, 50, 75, 100 N) the axial displacement between the various specimens did not show any significant differences. Under maximal axial force, the specimen fixed with the C-plate ( Fmax 2042 N) showed significantly better stability than the Arthrex plate ( Fmax 1687 N); P < 0.05. The AO plate ( Fmax 1612 N without bone graft and Fmax 1583 N with bone graft) showed the lowest axial exposure to stress. Moreover, the influence of the osteotomy angle (7.5 degrees, 10 degrees, 12.5 degrees, 15 degrees ) on axial stress resistance ( Fmax 2548, 2090, 1975, and 1740, respectively) was evaluated, and a direct correlation was found ( R = 0.794, P < 0.05).

Cartilage resurfacing: filling defects

Chondral defects with no significant bone involvement can be managed arthroscopically using surface treatments such as debridement and drilling, abrasion arthroplasty, and microfracture. Chondral defects can also be managed arthroscopically using osteochondral autografts (mosaicplasty) or by cartilage cell transplant or periosteal grafts, both of which are performed in open surgery. The arthroscopic surface treatments are best reserved for small defects, but cell transplantation and mosaicplasty have been used for defects up to 3 cm in diameter. Periosteal grafting can be used for large defects affecting an entire condyle, but clinical experience with this procedure is limited and it is still considered investigational. Larger osteochondral defects (uncontained defects greater than 3 cm in diameter and greater than 1 cm in depth) are managed using osteochondral allografts. Realignment osteotomy should be considered in conjunction with any of these techniques in the presence of a coexisting deformity.

Use of a lateral offset short-leg walking cast before high tibial osteotomy

The clinical results after high tibial osteotomy for the treatment of symptomatic varus gonarthrosis are unpredictable. Although preoperative gait analysis has been shown to be useful in predicting successful outcome after high tibial osteotomy, there are no readily available preoperative clinical tests for predicting success. The authors did a study to determine the effects of an offset short-leg walking cast as a potential predictor of clinical success after high tibial osteotomy. Specifically, the authors evaluated the effect of an offset short-leg walking cast on pain relief and changes in the peak external adduction moments in patients with symptomatic varus gonarthrosis indicated for high tibial osteotomy. Nineteen consecutive patients indicated for high tibial osteotomy were enrolled and completed the study. All patients had precast gait analysis to determine baseline parameters. Immediately after gait analysis, a short-leg lateral offset walking cast was applied and worn for 3 days to allow time for adaptation. Gait analysis then was repeated. Western Ontario and McMaster Universities Osteoarthritis Index pain scores were obtained before and after the cast was applied. The cast resulted in a mean reduction in pain of 53%, and a mean reduction in the peak external adduction moment of 36% in the 17 of 19 patients who tolerated the cast. The reduction in pain was correlated with the reduction in the peak adduction moment (r = 0.63). The authors conclude that an offset short-leg walking cast results in pain reduction that correlates with changes in external adduction moments about the knee. Therefore, an offset short-leg walking cast may prove to be an effective tool for predicting patients who ultimately will benefit from valgus high tibial osteotomy.

Medial opening-wedge high tibial osteotomy with use of porous hydroxyapatite to treat medial compartment osteoarthritis of the knee

BACKGROUND

The aims of this study were to investigate the results of opening-wedge high tibial valgus osteotomy in patients with medial compartment osteoarthritis of the knee and to examine the usefulness of hydroxyapatite wedges as the supporting material.

METHODS

Medial opening-wedge osteotomy was performed in twenty-one osteoarthritic knees in eighteen patients who had a mean age of 66.6 years. The mean duration of follow-up was 78.6 months. A medial transverse osteotomy was performed proximal to the tibial tuberosity, with the most lateral 10% of the tibia left intact. The medial side of the osteotomy site was opened to the desired angle of correction. Two hydroxyapatite wedges of the same size (5.0, 7.5, or 10.0 mm) were inserted into the opened osteotomy site along with bone grafts, and the fragments were fixed with two plates. The angle of correction could be adjusted by altering the direction of wedge insertion. The goal was to achieve a final standing alignment of 10 degrees of anatomical valgus angulation.

RESULTS

All patients had pain relief and improvement in walking ability after the osteotomy. The mean knee and function scores of the American Knee Society were 60.2 +/- 5.3 and 48.1 +/- 10.4 points, respectively, before the osteotomy and 94.3 +/- 7.3 and 93.1 +/- 9.8 points, respectively, at the time of the final follow-up. Limb alignment, expressed as the standing femorotibial angle, was corrected from 180 degrees +/- 2.9 degrees preoperatively to 169.7 degrees +/- 3.7 degrees (10.3 degrees of anatomical valgus angulation) at the time of the latest follow-up. There were no cases of recurrence of varus deformity or collapse of the hydroxyapatite wedges.

CONCLUSIONS

After a mean duration of follow-up of 6.6 years, we found that the medial opening-wedge osteotomy of the proximal part of the tibia provided satisfactory clinical results for patients with osteoarthritis of the knee. Use of the porous hydroxyapatite wedges resulted in no collapse or subsidence at the osteotomy site.

LEVEL OF EVIDENCE

Therapeutic study, Level IV (case series [no, or historical, control group]). See p. 2 for complete description of levels of evidence.

Arthritis and osteotomies in anterior cruciate ligament reconstruction

Unfortunately, young patients with active life-styles who present with an ACL-deficient knee and early evidence of arthritis remain a very difficult population to treat. Arthroscopic ACL reconstruction is a proven and effective way to treat patients with anterior knee instability [2]. In addition, numerous authors have demonstrated that knee osteotomies are effective in addressing isolated medial or lateral compartment degenerative disease, even in the presence of anterior knee instability [7, 9, 22, 43]. A comprehensive evaluation of pain, alignment, and stability are necessary in order to formulate the best treatment plan for each patient. Patients with combined chronic instability secondary to ACL insufficiency and unicompartmental arthritis will generally benefit from arthroscopic debridement, ACL reconstruction, knee osteotomy, or any combination thereof. Expectations of patients should be managed according to their underlying pathology, and this is a critical component for the success of the surgery. Most patients will get some degree of symptomatic relief and functional improvement. A return to competitive or high-level sports is an unrealistic goal, however, and should be discouraged.

Increase in range of knee motion to obtain floor sitting after high tibial osteotomy for osteoarthritis

In order to obtain better range of motion in knees with osteoarthritis, medial and lateral parapatellar retinaculo-capsular release operations were performed at the time of high tibial osteotomy, with fixation using dual plating on medial compartmental knee osteoarthritis (29 knees) or spontaneous osteonecrosis of the medial femoral condyle (15 knees). At removal of the blade plate, 1 to 2 years after the initial osteotomy, the same release procedures were performed together with resection of adhesive soft tissue and resection of osteophytes, which were obstacles to full flexion. A grading system (Grade 0-3) was proposed to evaluate the duration (min) of formal floor sitting. After these procedures, the patients were able to sit on the floor with 155-165 degrees of flexion for more than 30 min (Grade 3) in 20 knees, for 10-29 min (Grade 2) in seven, for less than 10 min (Grade 1) in nine and were unable to sit on the floor (Grade 0) in eight knees. Maximum knee flexion and total range of motion were 142+/-8.4 degrees and 137+/-11 degrees before and 152+/-6.6 degrees and 151+/-7.4 degrees after surgery, respectively. The American Knee Society Knee Score and Function Score were 61+/-17 and 46+/-16 before, and 97+/-5 (P<0.0001) and 91+/-13 (P<0.0001) after surgery at the final follow-up, respectively. The femoro-tibial angle in standing with one leg was 183+/-6 degrees (3 degrees of anatomical varus angulation) before and 170+/-3 degrees (P<0.0001) (10 degrees of anatomical valgus angulation) after surgery.

Double level osteotomy of the knee: a method to retain joint-line obliquity. Clinical results

BACKGROUND

Although general guidelines have been proposed for proximal tibial and supracondylar osteotomies, double level osteotomy provides the advantage of maintaining neutral joint-line obliquity in addition to correcting limb malalignment around the knee. The goal of this prospective study was to determine the outcome of double level osteotomy of the knee performed after analysis with computer-aided preoperative planning software in patients with varus malalignment.

METHODS

Twenty-nine double level osteotomies of the knee were performed in twenty-four patients. The patients were followed for an average duration of 82.7 months (range, twenty-seven to 137 months). All knees had moderate-to-severe varus deformity and arthritis. The mean preoperative mechanical tibiofemoral angle was 193.9 degrees (that is, 13.9 degrees of varus). Preoperative and postoperative evaluations included clinical (scores according to the Knee Society system), radiographic, and computer-aided analysis of the mechanical status of the knee joint. Failure was defined as conversion of an osteotomy to a total knee arthroplasty or the presence of severe pain in a patient who declined arthroplasty.

RESULTS

The mean clinical and functional scores according to the Knee Society system improved from 34 and 64 points, respectively, before the osteotomy to 90 (p < 0.0001) and 81 points (p = 0.079) at the time of the final follow-up examination. One patient was lost to follow-up. One of the twenty-nine knees was subsequently converted to total knee arthroplasty forty-nine months postoperatively. The cumulative rate of survival at 100 months was 96% (95% confidence interval, +4.5 to -8.7), with eight patients remaining at risk.

CONCLUSIONS

Double osteotomy is a valuable procedure for patients with such a large varus deformity that appropriate realignment and load transfer to the unaffected compartment, together with an acceptable joint-line obliquity, cannot be achieved by a single osteotomy.

Osteotomy of the knee: is there a seat at the table?

Osteotomy is an alternative treatment for unicompartmental osteoarthritis of the knee. In genu varum, a high valgus closing wedge osteotomy is preferred, with overcorrection by 5 degrees. Complications and poor outcomes can be overcome by incomplete osteotomy with careful preoperative planning, precise use of cutting jigs, compression fixation, and early mobilization and weight bearing. Patella baja is related to postoperative immobilization, and unicompartmental arthroplasties are more difficult to revise because of bone loss. Supracondylar femoral osteotomy is preferred for genu valgum using a lateral opening wedge with a toothed plate, allowing easy access to the lateral compartment of the knee. Osteotomy, far from being obsolete, has an increasing role in joint resurfacing procedures.

Articular cartilage repair: basic science and clinical progress. A review of the current status and prospects

OBJECTIVE

To review the basic scientific status of repair in articular cartilage tissue and to assess the efficiency of current clinical therapies instigated for the treatment of structural lesions generated therein as a result of trauma or during the course of various diseases, notably osteoarthritis (OA). Current scientific trends and possible directions for the future will also be discussed.

DESIGN

A systematic and critical analysis is undertaken, beginning with a description of the spontaneous repair responses in different types of lesion. Surgical interventions aimed at inducing repair without the use of active biologics will then be considered, followed by those involving active biologics and those drawing on autogenic and allogeneic tissue transplantation principles. Cell transplantation approaches, in particular novel tissue engineering concepts, will be critically presented. These will include growth-factor-based biological treatments and gene transfection protocols. A number of technical problems associated with repair interventions, such as tissue integration, tissue retention and the role of mechanical factors, will also be analysed.

RESULTS

A critical analysis of the literature reveals the existence of many novel and very promising biologically-based approaches for the induction of articular cartilage repair, the vast majority of which are still at an experimental phase of development. But prospective, double-blinded clinical trials comparing currently practiced surgical treatments have, unfortunately, not been undertaken.

CONCLUSION

The existence of many new and encouraging biological approaches to cartilage repair justifies the future investment of time and money in this research area, particularly given the extremely high socio-economic importance of such therapeutic strategies in the prevention and treatment of these common joint diseases and traumas. Clinical epidemiological and prospective trials are, moreover, urgently needed for an objective, scientific appraisal of current therapies and future novel approaches.