Treatment Of Medial Compartment Osteoarthritis Research Articles

The Repicci II® Unicondylar Knee Arthroplasty: 9-year Survivorship and Function

Unicompartmental knee arthroplasty (UKA) is a recognized procedure for treatment of medial compartment osteoarthritis. UKA using minimally invasive surgery (MIS) has the theoretical advantage of less bone resection and quicker rehabilitation. Whether the function of patients with UKA compares with that of patients with conventional TKA is unclear. We determined (1) the length of stay and complications associated with a short-stay MIS protocol; (2) whether MIS techniques allow for accurate positioning of the implant and alignment of the limb; (3) the change in functional scores; (4) the revision rate, reasons for revision, and survival of this implant. We prospectively followed 100 patients who had 114 UKAs. All completed an International Knee Society (IKS) score preoperatively, at 1 year, and at last followup. We determined survivorship. Minimum followup was 5.2 years (mean, 7.4 years; range, 5.2-9 years). Mean length of stay was 1.2 days, with 41% discharged the same day. The perioperative complication rate was 6%. The mean IKS score improved from 77 to 93 and was 86 at last followup. The mean hip-knee-ankle axis changed from 6° varus to 1.7° varus. Twenty-two patients underwent a revision procedure at a mean 6.2 years after the index procedure. Survivorship of the prosthesis was 78% at 9 years. The short-stay protocol was not associated with a high perioperative complication rate. This technique is associated with improvement in function and restoration of limb alignment, allowing accurate positioning of the implant. Compared with other reports of survival of UKA, this implant had a lower survivorship and increased revision rate.

Short-term results of the Oxford phase 3 unicompartmental knee arthroplasty for medial arthritis

We evaluated short-term results of the Oxford phase 3 unicompartmental knee arthroplasty (UKA) in patients with medial compartment arthritis. The study included 38 patients (28 females, 10 males; mean age 67 years; range 56 to 75 years) who underwent UKA for isolated medial knee osteoarthritis. At the time of surgery, 28 patients were in the age group of 56-64 years, and 10 patients were in the age group of 65-75 years. All the patients had Ahlbäck grade 2 primary medial compartment arthritis that had been unresponsive to conservative treatment. None of the patients had symptoms of patellofemoral arthrosis. Patients underwent UKA with the Oxford phase 3 cemented meniscal-bearing unicondylar prosthesis using minimally invasive surgery. The results were assessed preoperatively and at final controls according to the Knee Society clinical and functional rating system. Postoperative radiographic evaluations were made according to the Oxford criteria. The mean follow-up period was 24 months (range 18 to 32 months). The mean preoperative active knee flexion increased from 121.8 degrees (range 110 degrees to 130 degrees ) to 130.9 degrees (range 120 degrees to 140 degrees) postoperatively (p<0.05). There was no limitation in knee extension both pre- and postoperatively. The mean preoperative and postoperative knee scores were 64.6 (range 47 to 80) and 97.5 (range 89 to 100), and the mean functional scores were 59.6 (range 45 to 80) and 92.1 (range 70 to 100), respectively (p<0.05). All the patients had an excellent knee score, while functional scores were excellent in 27 patients (71.1%) and good in 11 patients (28.9%). Postoperative radiographic measurements showed that the position of the femoral components was within acceptable ranges in all the patients with a mean of 3 degrees valgus (range 5 degrees valgus to 8 degrees varus) and 0.5 degrees extension (range 3 degrees extension to 2 degrees flexion). The positioning of the femoral components in relation to the mechanical axis was central in 30 patients and 2-mm lateral (range 2 mm medial to 4 mm lateral) in eight patients. The position of the tibial components was also within acceptable ranges in all the patients with a mean of 1.5 degrees varus (range 2 degrees varus to 2 degrees valgus) and a mean posterior inclination of 6.2 degrees (range 5 degrees to 7 degrees). All the tibial components showed full congruency with the medial, lateral, anterior, and posterior planes, except for one which had a 4-mm undersizing in the anterior plane. The polyethylene insert was central and parallel to the tibial component in all the patients. No osteophytes or cement debris that might lead to impingement were observed. All the components remained in position until the final controls. Complications such as insert dislocation, infection, pulmonary embolism, deep venous thrombosis, or neurovascular injury were not observed. None of the patients required revision surgery. Our findings show that, with proper patient selection and strict adherence to the surgical technique, short-term results of the Oxford phase 3 unicompartmental knee prosthesis are excellent or good in the treatment of medial compartment osteoarthritis.

High tibial osteotomy compared with unicompartmental arthroplasty for the treatment of medial compartment osteoarthritis: a meta-analysis

Background The objective of our meta-analysis was to compare the clinical outcomes of high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) for the treatment of isolated medial compartment osteoarthritis (OA). Methods We searched the major medical databases for randomized trials and observational studies comparing HTO and UKA. After testing for publication bias and heterogeneity, the data were aggregated by fixed-effects modeling. Our primary outcome was the percentage of good or excellent outcomes in each group. Our secondary outcomes were implant survivorship and change in gait velocity. Results Six studies met our inclusion criteria for review. We found no evidence of publication bias or heterogeneity between studies for all outcome measures. The combined odds ratio for a good or excellent outcome in the UKA group was 2.03 (95% CI: 1.16 to 3.6) P = 0.01. The combined odds ratio for survival from aseptic loosening for the UKA group was 2.14 (95% CI: 0.93 to 4.93) P = 0.07. The pooled mean difference for gait velocity was 0.39 (95% CI: −0.12 to 0.90), P = 0.14. Conclusion UKA yields a greater percentage of good or excellent outcomes and a strong trend towards improved survivorship over HTO for medial compartment OA. Level of Evidence: Therapeutic Level II.

The Role of Unicompartmental Knee Arthroplasty Versus Total Knee Arthroplasty in Providing Maximal Performance and Satisfaction

Unicondylar knee arthroplasty (UKA) and total knee arthroplasty (TKA) are both recommended for the treatment of medial compartment osteoarthritis in the varus knee. Some authors report favorable functional results and patient satisfaction from TKA on the basis of extensive, long-term success of knee arthroplasty. Others cite the arduous rehabilitation and bone loss associated with traditional knee arthroplasty, opting for UKA, especially in young, high-demand patients. This article reviews the elements of successful UKA. It emphasizes the advantages of UKA versus traditional knee arthroplasty and minimally invasive TKA.

High Tibial Osteotomy for Medial Compartment Osteoarthritis: A Comparison of Clinical and Radiological Results from Closed Wedge and Focal Dome Osteotomies

This study aimed to evaluate the clinical and radiological results of closed wedge osteotomy (11 knees) and focal dome osteotomy (14 knees) in cases of high tibial osteotomy undertaken for varus knee with medial compartment osteoarthritis. Clinical evaluation was performed using the Knee Society Score and no significant difference was seen between the two groups at final follow-up. Radiological evaluation was made on the basis of the pre- and postoperative mechanical axis, postoperative movement of the tibial axis, loss of correction at final follow-up and patellar height measured using the Insall-Salvati index. Statistically significant differences were seen with focal dome osteotomy compared with closed wedge osteotomy in the InsallSalvati index at final follow-up, the amount of correction loss and the change in tibial axis location. It is concluded that, in the treatment of medial compartment osteoarthritis by high tibial osteotomy, focal dome osteotomy is more beneficial than closed wedge osteotomy in not creating any additional deformity.

Bone ingrowth in macroporous Bonelike ® for orthopaedic applications

The aim of this study was to evaluate the biological behaviour of porous scaffold structures of Bonelike ® which is suitable for either direct clinical use or tissue engineering applications. Porous cylindrical specimens 8 × 10 mm were implanted in the lateral aspect of the tibia of 13 patients (mean age 54 years), during osteotomy surgery for the treatment of medial compartment osteoarthritis of the knee. Implanted cylinders were retrieved at the same time as the removal of the blade plates at 3, 6, 9 and 12 months. Scanning electron microscopy and histological evaluations were performed to observe the biological responses of human bone tissue to porous Bonelike ®. The penetration depth was determined for all implantation periods, and after 6 months it was already possible to see new bone in the centre of the implanted cylinders, which gives 100% of penetration depth for all implantations periods except for 3 months when bone could only be seen in the peripherical region. Regarding the percentage of the area covered by new bone calculated from two-dimensional histological sections, values of 53 ± 15, 76 ± 12 and 88 ± 9% were achieved for 6, 9 and 12 months, respectively. Due to its structural features porous Bonelike ® permitted effective vascularization and bone ingrowth, and therefore was fully osteointegrated as shown in the histological surveys. A slow biomaterial degradation with implantation time is envisaged since the material has displayed surface degradation. Bonelike ® scaffolds show potential for complete ingrowth of osseous tissue and restoration of vascularization throughout the defected site.

Opening wedge high tibial osteotomy using 3D biomodelling Bonelike® macroporous structures: case report

Two synthetic calcium phosphates in porous wedge shape, Bonelike and a commercial HA/beta-TCP biphasic material, were used as an alternative to bone autografts and allografts in the treatment of medial compartment osteoarthritis of varus knees. The structure of Bonelike has a 3D architecture that is computer controlled, and a composition that mimics the mineral composition of natural bone. The HA/beta-TCP biphasic material used as a control material in this study was prepared using conventional foaming based methods. No signs of inflammatory reactions were observed post-operatively for both materials. After 4 months signs of fusion at the osteotomy site and good integration of the implanted wedges were observed, showing good mechanical resistance. Concerning the final correction attained, the left knee revealed a satisfactory valgus of 10 degrees , but the right one only had a final value of 6 degrees . The clinical evaluation using International Knee Score (IKS) showed good outcome in all parameters with complete range of motion in both knees and climbing stairs without crutches with only slight pain.

Patient, Implant, and Alignment Factors Associated With Revision of Medial Compartment Unicondylar Arthroplasty

The investigators reviewed 245 fixed-bearing unicondylar arthroplasties that one surgeon performed as treatment of medial compartment osteoarthritis between 1988 and 1997 using a variety of cemented metal-backed tibial components and gamma-irradiated-in-air polyethylene bearings. Multivariate statistical analysis was used to evaluate how the event of revision was influenced by 3 patient factors, 3 implant factors, and 7 factors assessed from preoperative and early postoperative radiographs. Five factors were statistically associated with revision: (younger) patient age, (thinner) tibial component initial thickness, (longer) polyethylene shelf age, (lesser) angular reduction of medial tibial plateau varus, and (more varus) postoperative hip-knee-ankle angle. Besides illustrating deleterious consequences of using gamma-irradiated-in-air polyethylene in medial unicompartmental arthroplasty, our results support reducing varus angulation of the medial tibial plateau and knee at surgery.

Use of Laterally Wedged Custom Foot Orthoses to Reduce Pain Associated with Medial Knee Osteoarthritis

Osteoarthritis of the knee is a common condition that can cause considerable pain and disability. Various forms of lateral wedging may be effective in the treatment of medial compartment osteoarthritis, but it is not known whether incorporating a lateral wedge into a custom-molded foot orthosis will achieve similar results. Therefore, 30 subjects (21 men and 9 women) aged 29 to 77 years (mean +/- SD, 58.1 +/- 11.6 years) with radiographically confirmed medial compartment knee osteoarthritis were issued custom-molded foot orthoses with a 5 degrees lateral heel wedge. Pain levels were recorded using a 100-mm visual analog pain scale on the date of issue of the orthoses (baseline) and again 3 and 6 weeks later. Mean +/- SD pain levels were significantly reduced at 3 weeks (34 +/- 22 mm) and 6 weeks (23 +/- 22 mm) versus baseline (69 +/- 19 mm) (F2 = 39.57). The degree of pain reduction was greater in patients with less severe osteoarthritis. At 6 weeks, all subjects had achieved at least some reduction in pain, and 28 reported that their orthoses were comfortable. This preliminary study indicates that laterally wedged foot orthoses may be beneficial in the treatment of mild-to-moderate osteoarthritis of the medial compartment of the knee. Further investigations using a larger sample, longer follow-up, and a no-treatment control group seem warranted.

Implementation, accuracy evaluation, and preliminary clinical trial of a CT-free navigation system for high tibial opening wedge osteotomy

Objective: The objectives of this study are to design and evaluate a CT-free intra-operative planning and navigation system for high tibial opening wedge osteotomy. This is a widely accepted treatment for medial compartment osteoarthritis and other lower extremity deformities, particularly in young and active patients for whom total knee replacement is not advised. However, it is a technically demanding procedure. Conventional preoperative planning and surgical techniques have so far been inaccurate, and often resulting in postoperative malalignment representing either under- or over-correction, which is the main reason for poor long-term results. In addition, conventional techniques have the potential to damage the lateral hinge cortex and tibial neurovascular structures, which may cause fixation failure, loss of correction, or peroneal nerve paralysis. All these common problems can be addressed by the use of a surgical navigation system.Materials and Methods: Surgical instruments are tracked optically with the SurgiGATE® navigation system (PRAXIM MediVision, La Tronche, France). Following exposure, dynamical reference bases are attached to the femur, tibia, and proximal fragment of the tibia. A patient-specific coordinate system is then established, on the basis of registered anatomical landmarks. After intra-operative deformity measurement and correction planning, the osteotomy is performed under navigational guidance. The deformities are corrected by realigning the mechanical axis of the affected limb from the diseased medial compartment to the healthy lateral side. The wedge size, joint line orientation, and tibial plateau slope are monitored during correction. Besides correcting uni-planar varus deformities, the system provides the functionality to correct complex multi-planar deformities with a single cut. Furthermore, with on-the-fly visualization of surgical instruments on multiple fluoroscopic images, penetration of the hinge cortex and damage to the neurovascular structures due to an inappropriate osteotomy can be avoided.Results: The laboratory evaluation with a plastic bone model (Synbone AG, Davos, Switzerland) shows that the error of deformity correction is <1.7° (95% confidence interval) in the frontal plane and <2.3° (95% confidence interval) in the sagittal plane. The preliminary clinical trial confirms these results.Conclusion: A novel CT-free navigation system for high tibial osteotomy has been developed and evaluated, which holds the promise of improved accuracy, reliability, and safety of this procedure.

Computer aided high tibial open wedge osteotomy

High tibial osteotomy is a widely accepted treatment of medial compartment osteoarthritis as well as other lower extremity deformities. However, it is a technically demanding procedure. The lack of exact intraoperative real time control of the mechanical axis often results in postoperative malalignments, which is one reason for poor long term results. These problems can be addressed with the use of a surgical navigation system. Following exposure, dynamic reference bases (DRBs) are attached to the femur, and the proximal and the distal part of the tibia. After intraoperative measurement of the deformities and correction planning, the osteotomy is performed under navigational guidance. The wedge size, joint line orientation, and tibial plateau slope are monitored during correction. The in vitro evaluation with a plastic bone model suggests that the error of deformity correction is less than 1.7 degrees (95% confidence limits) in the frontal, and less than 2.3 degrees (95% confidence limits) in the sagittal plane, respectively. On a cadaver study of 13 legs, the mechanical axis intersected the Fujisawa line in 80.7% (range 77.5-85.8%). The preliminary clinical experience confirms these results. A novel computer tomography free navigation system for high tibial osteotomy has been developed that holds the promise of improving the accuracy, reliability, and safety of this kind of approach.

Intra-operative findings in varus osteoarthritis of the knee

Interest in unicompartmental knee arthroplasty (UKA) for the treatment of medial compartment osteoarthritis has increased in recent years with apparent improvement in the long-term results. This is a result of improved surgical technique, patient selection, and implant design. In an effort further to improve patient selection we analysed the relationship between the pre-operative alignment of the knee and the anatomical findings at the time of surgery. We compared these findings with the indications for UKA. From 4021 total knee arthroplasties we compared intra-operative observations with the pre-operative clinical data in order to identify knees with isolated, medial, compartment changes, which would have been ideal candidates for UKA. We found that only 247 of the knees (6.1%) met anatomical qualifications for isolated, medial, unicompartmental osteoarthritis, and of these, only 168 (4.3%) met clinical standards ideal for UKA. Preoperative alignment showed a significant relationship with patterns of disease. Logistic regression revealed a relationship between pre-operative alignment and intraoperative findings resembling a Gaussian distribution. Patients with a pre-operative varus alignment of 7 degrees were slightly more likely to be selected for UKA. But the further the anatomical alignment in either direction varies from 7 degrees of varus, the more unlikely it is for the knee to exhibit a disease pattern of isolated, medial, unicompartmental osteoarthritis.

Paper #137 Minimally invasive treatment of medial compartment osteoarthritis of the knee using a polyurethane spacer: a new technique

Unicondylar arthroplasty (UKA), an almost forgotten option for the arthritic knee, has experienced a resurgence of interest with the Introduction of minimally invasive surgery (ENGH 2002). SCULCO (1994) described UKA as treatment of choice in unicompartmental arthritis of the knee, when arthroplasty is indicated. Advantages over total knee arthroplasty (TKA) are preservation of cruciate ligaments as well as other undamaged structures along with possible restoration of knee function to nearly normal. Patellar dislocation is not necessary as part of the procedure, and hospitalisation can be avoided. We report an extension of UKA using an even less invasive surgical technique to insert a spacer between the femur and tibia for treatment of medial compartment osteoarthritis.