Medial Compartment Arthritis Research Articles

Treatment of Medial Compartment Arthritis of the Knee: A Survey of the American Association of Hip and Knee Surgeons

Medial compartmental arthritis of the knee is a common orthopedic problem. This study surveyed active members of the American Association of Hip and Knee Surgeons on recommended surgical treatment of this condition. A response rate of 30.8% was obtained. One third of respondents (32.9%) reported patient age as the most important factor in determining surgical treatment. Total knee arthroplasty (89.2%) and arthroscopy (87.2%) were the most widely reported surgical treatments. Most respondents (73.7%) rated experience as the primary basis in determining factors for surgical recommendations. Case scenarios revealed age and gender having significant bearing on treatment recommendations. These results suggest that age and degree of deformity are 2 important considerations in surgical treatment of medial compartment arthritis and, among this group of respondents, influence the wide variety of treatment options.

High-Performance Alternatives to Total Knee Arthroplasty

The surgical management of medial compartment osteoarthritis in the varus knee includes total knee arthroplasty, unicondylar arthroplasty, and proximal tibial osteotomy. While some authors report favorable results from arthroplasty surgery in young patients, 1 others prefer to avoid traditional arthroplasty in young patients. Young adults with varus knees develop severe medial compartment arthritis early in life. The relationship between alignment and progression of osteoarthritis has been demonstrated within 18 months of clinical follow-up. 2 Varus alignment contributes to medial meniscus tears, poor results after medial meniscectomy, and medial compartment osteoarthritis.

Unicondylar knee arthroplasty in unicompartment osteoarthrits : Early results

Background: Knee Arthritis in most patients begins and remains confined to medial compartment. Unicondylar knee replacement (UKR) can be better alternative in these selected patients. Methods: Eighty one consecutive unicondylar knee arthroplasties in 60 patients of isolated medial compartment arthritis were done using Allegrato unicondylar knee. Patients were followed up at 6­month interval with average follow up 1.8 yrs. Knee society score was used for comparative evaluation of these patients. Results: The mean pre operative knee society score of 62 improved to post op. score of 94. No complication reported so far except one case of tibial base plate dislocation requiring re fixation. Our short-term results are good to excellent with 100 % survival at avg. follow up of 1.8 years. Conclusion: UKA is better alternative with many advantages in selected patients of early symptomatic medial compartment arthritis. However proper patient selection improvised design, exacting surgical technique and experienced team with established center are must for uncompromising results.

UniSpacer Arthroplasty of the Knee

The operative treatment of medial compartment knee arthritis is controversial. The purpose of the present study was to report the experience of a single surgeon with the UniSpacer arthroplasty for the treatment of isolated medial compartment arthritis of the knee. From April 2002 through November 2002, thirty-seven UniSpacer arthroplasties were performed in thirty-four patients for the treatment of arthritis that primarily involved the medial compartment of the knee. The Ahlbäck radiographic evaluation scale was used to grade the severity of arthritis; the mean preoperative score was 2.6 points for the medial compartment and 0.5 point for both the lateral and patellofemoral compartments. The study group included eighteen women (nineteen knees) and sixteen men (eighteen knees) who had a mean age of fifty-five years (range, forty-two to seventy-five years) at the time of surgery. Twelve patients had had a previous arthroscopic meniscectomy. The mean preoperative Knee Society function score was 60 points (range, 40 to 80 points), and the mean preoperative Knee Society objective score was 62 points (range, 40 to 76 points). After a mean duration of follow-up of twenty-six months (range, twenty-four to twenty-nine months), there were no excellent, ten good, fifteen fair, and twelve poor results. The mean postoperative total function score was 69 points (range, 40 to 82 points), and the mean Knee Society objective score was 72 points (range, 45 to 88 points). Six of the twelve poor results were in knees that had dislocation of the UniSpacer. All twelve knees were revised to a total knee arthroplasty. On the basis of this experience, we do not recommend UniSpacer arthroplasty for the treatment of degenerative arthritis of the medial compartment of the knee.

Medium-term results of the AMC-unicompartmental knee arthroplasty

This study presents the outcome of patients treated by AMC-unicompartmental knee arthroplasty (UCA). The prosthesis was implanted in 361 cases for the medial or lateral compartment arthritis. The mean follow-up period was 5.5 (range: 2.3–12.5) years. Mean age at surgery was 69.5 (range: 46.3–88.6) years. Six knees were lost to follow-up (1.6%). Patients were assessed by an independent clinical observer and results were standardised using the Knee Society Rating System. The roentgenographic analyses were performed according to the Knee Society Evaluation System. Ninety-five percent of patients had no pain or slight pain at the latest follow-up, 92% had a good or excellent clinical outcome. Three knees were revised for mobile bearing dislocation after medial UCA and three for lateral mobile bearing dislocation after lateral UCA. Five revisions were necessitated by component loosening and there was one case of deep infection. The clinical results of the investigated patients demonstrate that the AMC-UCA is a successful concept with safe fixation of the prosthesis and good durability of the mobile bearings.

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° of internal rotation (mean ± SD), ranging from 8° of external rotation to 14° of internal rotation; the mean changes in FTA and HKA were 3.5 ± 2.2° (range, 0.4–8.6) and 1.6 ± 1.3° (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° for internal and external 10° 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.

Delayed- and non-union following opening wedge high tibial osteotomy: surgeons' results from 182 completed cases.

Opening wedge high tibial osteotomy (OWHTO) is a recently described procedure for medial compartment arthritis of the knee in the active, younger population. Despite having a number of advantages over the traditional closing wedge high tibial osteotomy (CWHTO) a potential complication of OWHTO is a high rate of delayed- and non-union. This study reports the occurrence of delayed- and non-union following OWHTO for medial compartment arthritis of the knee. Questionnaires were sent to all current members of the Australian Knee Society (n=45), a special interest group of the Australian Orthopaedic Group. Surgeons were asked primarily to indicate how many OWHTOs they had performed, and how many of these had progressed to union, delayed-union and non-union. All 45 questionnaires were returned, with 21 surgeons (47%) performing OWHTOs. A total of 188 OWHTO cases were reported, of which 182 were complete. Of these complete cases 167 (91.8%) were classed as united, 12 (6.6%) delay-united and 3 (1.6%) non-united. The results of this study demonstrate that the rate of delayed- and non-union following OWHTO for medial compartment arthritis of the knee is relatively low and comparable to that reported for traditional CWHTO.

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.

The effect of alignment of the knee on the outcome of unicompartmental knee replacement.

Many authors have recommended undercorrection of the deformity when carrying out unicompartmental knee arthroplasty (UKA). The isolated effect of alignment of the knee on the outcome of UKA has, however, received little attention. We reviewed 185 UKAs at a minimum of five years after surgery. They had been carried out by a single surgeon using metal-backed tibial components in the management of arthritis of the medial compartment. We measured the tibiofemoral angle (TFA) before and at four months after operation and at the most recent assessment. The amount of correction of the TFA and any subsequent loss were recorded. While adjusting for the effects of age, weight and gender of the patients and the type and thickness of the implants, the mean correction was significantly less for those with a Marmor rating of failure (6.8 degrees) than for those rated excellent (9.2 degrees). The mean correction was also significantly less for patients with a Marmor rating of failure (6.8 degrees) than for those rated poor (11.1 degrees). The mean correction for the UKAs which were revised (6.6 degrees) was significantly less than for those not revised (9.1 degrees). Additionally, revised UKAs had a significantly higher percentage (63%) of thinner tibial implants (<8 mm) than the surviving UKAs (27%). These findings suggest that undercorrection of the TFA in UKA of the medial compartment should be avoided, particularly if a thin tibial polyethylene insert is used.

Comparison of two different techniques for high tibial osteotomy: internal fixation vs circular external fixator

Objectives: We evaluated the mid-term results of high tibial osteotomy in patients with medial compartment arthritis. Methods: The study included 46 patients (37 females, 9 males) with medial compartment arthritis. The patients were treated with high tibial osteotomy which was accompanied by either internal fixation (group A, 26 patients; mean age 52.4 years; range 43 to 58 years) or an external fixator (group B, 20 patients; mean age 51.7 years; range 42 to 59 years). All the patients had unilateral involvement (31 left, 15 right). Clinical evaluations were made using the HSS (Hospital for Special Surgery) scoring system. Radiographic evaluations consisted of mechanical axis alignment, knee joint orientation angles (lateral distal femoral angle - LDFA, medial proximal tibial angle - MPTA), and the Insall-Salvati index. The mean follow-up was 63.9 months (range 48 to 72 months) in group A, and 57.9 months (range 49 to 63 months) in group B. Results: The mean HSS score increased from 73.4 to 85.6 in group A. Postoperatively, the mean MPTA angle was 83° and LDFA angle was 90°; the mean mechanical axis was 2 mm medially, and the mean Insall-Salvati index was 0.76. In group B, the mean HSS score increased from 72.1 to 91.2, with the mean MPTA angle being 88°, LDFA angle being 89°, the mean mechanical axis being 10 mm laterally, and the mean Insall-Salvati index being 1.1. Conclusion: We concluded that high tibial osteotomy with a circular external fixator is successful and effective in the treatment of medial compartment arthritis.

The role of external fixation in antivarus tibial osteotomy

Genu varum is commonly associated with medial compartment arthritis, but it can also be idiopathic, posttraumatic,or a result of residual Blount's disease. Both the bony deformity and soft tissue deformity can be corrected by a proximal tibial osteotomy and Ilizarov frame placement. The goal is to improve the mechanical axis and correct the tension on the ligamentous and capsular structures. In this report, we describe the techniques for both the acute and gradual correction of germ varum. Posttraumatic deformity and medial compartment arthritis are best corrected acutely. Deformity because of idiopathic germ varum or residual Blount's disease is treated gradually to correct angular deformity and lengthen the tibia relative to the fibula. These techniques are safe, simple, and effective methods of addressing the deformity caused by genu varum and allow a rapid return to weight bearing. ilizarov external fixators are well tolerated, and patient satisfaction is high.

Management of Medial Collateral Ligament Laxity

Assessment of axial alignment with 3-foot radiographs and valgus-varus stress radiographs is important when managing symptomatic MCL instability. Realignment of the anatomical axis to 0 degrees to reduce the stress on the MCL reduces the symptomatic laxity. The assessment of MCL laxity is important when considering valgus HTO for medial compartment arthritis. A combined opening and closing wedge osteotomy reduces the size of the fragment needed and tensions the MCL at the same time. Interposition proximal tibial allografts may be used to retention combined MCL/LCL laxity as well as to correct associated deformities. As one would expect, defunctioning of the MCL in patients with valgus is best achieved using a varus distal femoral osteotomy.

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.