Accelerated degeneration of the discoid lateral meniscus after medial opening wedge high tibial osteotomy

Identical clinical outcomes between neutral and classic targeted alignments after high tibial osteotomy in medial meniscus posterior root tear: a prospective randomized study

PURPOSE

This study aimed to compare the clinical and radiographic outcomes and arthroscopic findings after high tibial osteotomy (HTO) between neutral and classic targeted coronal alignments in patients with medial meniscus posterior root tears (MMPRTs).

METHODS

Ninety-eight patients with MMPRT were prospectively enrolled in the final cohort and randomized into two groups. Fifty-two patients with the targeted alignment through the Fujisawa point (60-62.5% of the entire tibial plateau width measured from the medial side) during HTO were included in group A, whereas 46 patients with the targeted alignment through the point at 50-55% of the tibial plateau width were included in group B. The clinical and radiographic outcomes and second-look arthroscopic findings were statistically compared for comprehensive assessments.

RESULTS

After a mean follow-up of 37.1 months, we found no significant differences between the two groups regarding the final Lysholm (p = 0.205) and Hospital for Special Surgery scores (p = 0.084). However, we only observed significant differences between the two groups in terms of the final hip-knee-ankle angle, weight-bearing line ratio, and medial proximal tibial angle (p < 0.001). Second-look arthroscopy did not reveal a significant difference in meniscal healing rate (p = 0.786).

CONCLUSIONS

Performing HTO with the aim to achieve neutral alignment leads to similar clinical outcomes in patients with MMPRT compared to classic alignment. Although subsequent research is required, the current study provides clinical evidence for the safety and efficacy of the new targeted alignment during HTO, which may avoid long-term complications associated with overcorrection when using the traditional technique.

Cartilage Degeneration of the Lateral Compartment of the Knee at Second-Look Arthroscopy Is Associated With Deterioration of 10-Year Clinical Outcomes After Opening-Wedge High Tibial Osteotomy

PURPOSE

To identify the arthroscopic findings associated with deterioration of 10-year clinical outcomes after opening-wedge high tibial osteotomy (OWHTO) in patients with knee osteoarthritis.

METHODS

A total of 114 consecutive knees of 91 patients with knee osteoarthritis who underwent OWHTO between 2007 and 2011 were retrospectively reviewed. Of these patients, those who underwent second-look arthroscopy and were followed up for a minimum of 10 years were enrolled. The Knee Society Score (KSS) and hip-knee-ankle angle were assessed. Cartilage status was graded at the time of osteotomy (first look) and plate removal (second look) according to the International Cartilage Repair Society (ICRS) grading system. The KSS knee subscale score and function subscale score were assessed separately, and on the basis of the changes in each of these scores from 1 to 10 years postoperatively and the minimal clinically important difference (MCID), the patients were divided into 2 groups: deteriorated (deterioration of score ≥ MCID) and non-deteriorated (deterioration of score < MCID).

RESULTS

Sixty-nine knees were included in this study. The mean knee score improved continuously from 48.7 ± 11.3 preoperatively to 86.8 ± 10.3 at 1 year (P < .001), 87.5 ± 9.9 at 5 years (P < .001), and 86.5 ± 10.5 at 10 years (P < .001) postoperatively. The mean function score also improved continuously from 62.5 ± 12.1 preoperatively to 90.7 ± 12.9 at 1 year (P < .001), 91.6 ± 12.1 at 5 years (P < .001), and 88.5 ± 13.1 at 10 years (P < .001) postoperatively. Three knees underwent conversion to total knee arthroplasty within 10 years postoperatively. The deteriorated KSS group showed significantly progressed ICRS grades in the lateral compartment compared with the non-deteriorated KSS group. The ICRS grade in the lateral compartment at second-look arthroscopy was identified as the only significant factor associated with both knee score deterioration (odds ratio, 4.89; P = .03) and function score deterioration (odds ratio, 3.91; P = .03) on multivariable logistic regression analysis.

CONCLUSIONS

The presence of cartilage degeneration of the lateral compartment of the knee at second-look arthroscopy is associated with deterioration of long-term clinical outcomes after OWHTO.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Visualization of lateral meniscus extrusion during gait using dynamic ultrasonographic evaluation

PURPOSE

Medial meniscus extrusion is one of the risk factors for knee osteoarthritis (OA). However, lateral meniscus extrusion has not been discussed, and detailed information remains unknown. In particular, the lateral meniscus has high mobility and is expected to be difficult to evaluate in terms of its behavior under static conditions. Dynamic ultrasonographic evaluation was introduced to detect the dynamic behavior of the meniscus during walking. In this study, we aimed to investigate the behavior of the lateral meniscus during walking using dynamic ultrasonographic evaluation.

METHODS

Sixteen participants with knee OA were recruited in this study. The change of lateral meniscus extrusion during walking was recorded using ultrasonography. Medial and lateral meniscal extrusion during the stance phase was measured, and meniscal mobility was defined as the difference in meniscal extrusion between minimum and maximum values (mm), medial meniscal extrusion (∆MME), and lateral meniscal extrusion (∆LME), respectively. The walking cycle and gait forms of lateral thrust were also evaluated using three-dimensional motion analysis systems and analyzed in terms of the correlation with ∆MME and ∆LME.

RESULTS

The lateral meniscus was depicted in the articular plane, and extrusion decreased during the stance phase of the gait cycle. The ∆LME was significantly higher than the ∆MME (p < 0.01). There was a significant positive correlation between ∆LME and lateral thrust (r = 0.62, p < 0.05).

CONCLUSIONS

We found that dynamic ultrasonographic evaluation can be used to visualize lateral meniscus extrusion during walking, and that its behavior is correlated to the degree of lateral thrust.

High Tibial Osteotomies for the Treatment of Osteoarthritis of the Knee

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A high tibial osteotomy (HTO) is a joint-preserving procedure that can be used to treat symptomatic unicompartmental cartilage disorders in the presence of limb malalignment.

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Appropriate patient selection and careful preoperative planning are vital for optimizing outcomes.

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Based on past literature, correction of varus malalignment to 3° to 8° of valgus appears to lead to favorable results. Recently, there has been growing awareness that it is important to consider soft-tissue laxity during preoperative planning.

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Although there has been a recent trend toward performing opening-wedge rather than closing-wedge or dome HTOs for unicompartmental osteoarthritis, current data suggest that all 3 are acceptable techniques with varying complication profiles.

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Based on current evidence, an HTO provides pain relief, functional improvement, and a high rate of return to sport, with reported survivorship ranging from 74.7% to 97.6% and 66.0% to 90.4% at 10 and 15 years, respectively.

Joint Space Width Increases Medially and Decreases Laterally at Different Time Points After Medial Open-Wedge High Tibial Osteotomy

PURPOSE

To evaluate the serial changes in the joint space width (JSW) of the medial and lateral compartments after medial open-wedge high tibial osteotomy (MOWHTO) and its associated factors.

METHODS

The medial and lateral weight-bearing JSWs were measured on serial radiographs and analyzed preoperatively and postoperatively within 2 weeks, as well as at 3 months, 6 months, 1 year, and 2 years. Associations between the medial and lateral JSWs and age, body mass index, mechanical axis, correction angle, lateral distal femoral angle, medial proximal tibial angle, joint line convergence angle (JLCA), JLCA on stress radiographs, and arthroscopic cartilage status were examined. Clinical outcome was measured according to the Knee Society objective and functional scores.

RESULTS

Seventy-one patients who underwent MOWHTO with locking-plate fixation were analyzed. The respective mean medial and lateral JSWs on serial radiographs were as follows: 3.08 mm and 5.14 mm preoperatively, 3.10 mm and 4.63 mm postoperatively, 3.37 mm and 4.57 mm at 3 months, 3.40 mm and 4.59 mm at 6 months, 3.44 mm and 4.57 mm at 1 year, and 3.42 mm and 4.64 mm at 2 years. At 3 months, the medial JSW increased (P < .001), whereas the lateral JSW decreased immediately (P < .001). JSW showed no significant differences at other time points. Preoperative and postoperative JLCAs and medial femoral and tibial cartilage grades were associated with medial JSW changes (P = .021). However, no significant parameters were associated with decreases in the lateral JSW (P > .05). The postoperative Knee Society objective and functional scores improved and were maintained.

CONCLUSIONS

After MOWHTO, the medial JSW increased at 3 months postoperatively and the lateral JSW decreased immediately. The preoperative and postoperative JLCAs and the medial femoral and tibial cartilage grades were associated with the change in the medial JSW. However, no significant parameters were associated with the decrease in the lateral JSW.

LEVEL OF EVIDENCE

Level IV, case series of therapeutic study.

Open-wedge high tibial osteotomy in patients with discoid lateral meniscus

BACKGROUND

There are concerns about the progression of the lateral osteoarthritis (OA) should be taken into account when high tibial osteotomy (HTO) is performed in patients with discoid lateral meniscus (LM). This study evaluated the clinical results of HTO in patients with discoid LM and elucidated factors affecting the results.

METHODS

This study evaluated 32 female patients with varus deformity and medial OA. Patients with discoid LM (8 patients) or without discoid LM (24 patients) underwent open-wedge HTO. The mean age was 53.5 years and the mean follow-up period was 35 months. Clinical results, including the Hospital for Special Surgery (HSS) score, Knee Society knee score (KS) and function score (FS), were evaluated. The progression of OA in the lateral compartment was also evaluated. Finally, we evaluated the factors affecting the clinical results and OA progression in the lateral compartment.

RESULTS

Between two groups, all clinical scores were not different (p = 0.964, 0.963, and 0.559, respectively). Three of eight patients (37.5%) in the discoid group developed OA in the lateral compartment, whereas 2 of 24 patients (8.3%) in the control group developed such; however, this was not significantly different (p = 0.085). In discoid group, patients with undercorrection has higher KS relative to patients with acceptable correction (p = 0.044). Other clinical results and OA change in the lateral compartment were not affected by evaluated factors.

CONCLUSIONS

Patients who underwent open-wedge HTO showed the satisfactory clinical results and lateral OA progression regardless of the presence or absence discoid LM. However, when discoid LM was present, patients with undercorrection showed higher KS in comparison with patients with acceptable correction.

Changes in lower limb alignment and their effect on the functional outcome after treatment of varus degenerative OA knee by hemicallotasis using modular dynamic HTO fixator

OBJECTIVE

High tibial osteotomy (HTO) is an established procedure to treat medial compartmental osteoarthritis (OA) knee associated with varus deformity. It is well documented that precise correction of deformity and maintenance of correction achieved is important to ensure long term good results. This study was undertaken to record changes in radiological parameters and its effect on the functional outcomes in first two years following HTO done for varus degenerative OA kneeby hemicallotasis technique using HTO fixator.

METHODS

31 patients meeting our inclusion-exclusion criteria who underwent HTO by hemicallotasis method using self-adjusting unilateral HTO fixator were included in the study. Their femoro tibial angle (FTA), mechanical axis %, Insall- Salvati ratio, proximal tibial antero-posterior slope and knee injury and osteoarthritis outcome Score (KOOS) were recorded preoperatively, postoperatively at the time of removal of fixator, at 1 year and at 2 years.

RESULTS

The FTA and mechanical axis significantly improved from a mean of 183.12⁰ and -3.26% respectively preoperatively to 173.38⁰ and 61.81% at the time of removal of fixator but subsequently showed significant deterioration to 176.06⁰ and 57.96% at 1 year and further insignificant deterioration to 176.16⁰ and 57.74 at 2 years. The KOOS improved from mean 56.61 preoperatively to 70.48 at the time of fixator removal and further improved significantly to 85.68 at 1 year but significantly deteriorated to 84.54 at 2 years. The Insall-Salvati ratio, tibial slope showed no significant change throughout the study. Conclusion: Though desired alignment can be achieved by using the fixator, we found a significant deterioration in achieved radiological parameters after removal of fixator adversely affecting the functional outcome which is a matter of concern.

The proper correction of the mechanical axis in high tibial osteotomy with concomitant cartilage procedures-a retrospective comparative study

Background

The guidelines to correct the mechanical axis in high tibial osteotomy (HTO) have changed recently, and some studies have suggested that the correction of the mechanical axis should be based on the severity of cartilage defect. The purpose of this study was (1) to evaluate the radiographic and clinical outcomes of HTO with concomitant cartilage procedures and (2) to compare our method with conventional method regarding the mechanical axis correction.

Methods

Sixty-six knees which underwent opening wedge HTO with cartilage procedures were evaluated retrospectively. The mean age was 56.0 ± 8.3 years, and the average follow-up period was 35.9 ± 22.0 months (range, 24–93 months) with a minimum follow-up of 2 years. All patients were divided into two groups regarding the method of mechanical axis correction; the postoperative mechanical axis was shifted to 50–55% of the tibial plateau width in group I (n = 46) and to 62–66% according to the conventional method in group II (n = 20). Concomitant cartilage procedures were performed, and each technique of those was determined according to the cartilage status.

Results

The functional scores and visual analog scale for pain in all patients showed a significant improvement at the final follow-up, but there was no significant difference between two groups. The postoperative mechanical axis was the valgus axis of 0.7° in group I with average mechanical axis deviation (MAD) of 51.7%, whereas the valgus axis of 4.2° in group II with average MAD of 64.0%. In patients who underwent second-look arthroscopy, the cartilaginous regeneration could be obtained by cartilage procedures.

Conclusion

In HTO with concomitant cartilage procedures, the method to correct postoperative mechanical axis to the neutral or valgus axis less than 3° could be an effective and safe method to obtain reliable clinical outcomes without complications. Therefore, our method can be used as a selective technique to prevent complications related to the postoperative valgus alignment in patients who are needed much correction angle due to the preoperative severe varus alignment.

Study design

Retrospective comparative study, level III.

Discoid lateral meniscus can be overlooked by magnetic resonance imaging in patients with meniscal tears

PURPOSE

MRI evaluation of torn lateral meniscus was compared with arthroscopy. This study calculates the sensitivity, specificity, and accuracy of MRI in determining the presence or absence of discoid lateral meniscus (DLM) for different tear types.

METHODS

MR imaging of 156 knees with arthroscopically confirmed lateral meniscus tears was analysed. There were 78 knees (70 patients) in non-DLM group and 78 knees (74 patients) in DLM group on arthroscopy as the reference standard. The presence of DLM on MRI was determined by an orthopaedic surgeon and a radiologist, who were blinded to the arthroscopic findings. The presence of discoid meniscus on MRI was determined by coronal and sagittal measurements, considering the tear pattern of lateral meniscus. The tear pattern was categorized into six types based on arthroscopic findings: horizontal, longitudinal, radial, combined radial, degenerative, and complex tear. The sensitivity, specificity, and accuracy of MRI were calculated for each type of lateral meniscus tear. In addition, we analysed the reason for non-detection of discoid meniscus on preoperative MRI.

RESULT

The sensitivity for determining the presence of discoid meniscus was 58% for radial tear, 57% for combined radial tear, and 65% for longitudinal tear, whereas the specificity was 100% for all tear groups. In the presence of radial or longitudinal tear, the accuracy of MRI was significantly lower than having no radial and longitudinal tear (p < 0.001). The presence of discoid meniscus was not recognized on MRI because of large radial tear (12 knees), deformed bucket-handle tear (6 knees), and inverted flap tear (3 knees).

CONCLUSIONS

MRI was not successful in determining the presence or absence of DLM in radial tear, combined radial tear, and longitudinal tear. When there are large radial tear, deformed bucket-handle tear, and inverted flap tear in lateral meniscus, it is recommended to consider the possibility of DLM. This information can help to make accurate diagnosis of DLM, which allows appropriate surgical planning and facilitates patient's information on poor prognosis of DLM.

LEVEL OF EVIDENCE

Level I.

Large correction in opening wedge high tibial osteotomy with resultant joint-line obliquity induces excessive shear stress on the articular cartilage

PURPOSE

The purpose of this study was to analyse the resultant stress induced by joint-line obliquity after HTO for varus knee deformity using a three-dimensional (3D) finite element model analysis.

METHODS

The geometrical bone data used in this study were derived from commercially available human bone digital anatomy media. The 3D knee models were developed using 3D computer-aided design software. The articular surface was overlaid with a 2-mm-thick cartilage layer for both femoral and tibial condyles. Ligament structures were simulated based on properties reported in previous anatomical studies. Regarding the loading condition, isolated axial loads of 1200 N with lateral joint-line inclinations of 2.5°, 5°, 7.5°, and 10° in reference to the horizontal axis were applied to the femur to simulate the mechanical environment in a knee with joint-line obliquity.

RESULTS

A steep rise of shear stress in the medial compartment was noted in the model with obliquity of 5° or more. This laterally directed shear stress exhibited an incremental increase in accordance with the obliquity angle. The maximum shear stress value in the medial cartilage increased from 1.6 MPa for the normal knee to 3.3, 5.2, and 7.2 MPa in the joint-line obliquity models with 5°, 7.5°, and 10° of obliquity, respectively.

CONCLUSIONS

The effects of HTO for varus knee deformity on the amount/distribution of stresses in the articular cartilage were analysed using a 3D finite element model. It was shown that joint-line obliquity of more than 5° induced excessive shear stress in the tibial articular cartilage. A large amount of correction in OWHTO with a resultant joint-line obliquity of 5° or more may induce detrimental stress to the articular cartilage. Double-level osteotomy should be considered as a surgical option in this situation.

High tibial osteotomy accelerates lateral compartment osteoarthritis in discoid meniscus patients

PURPOSE

The valgus high tibial osteotomy (HTO) in patients with medial osteoarthritis and discoid lateral meniscus can result in increased load on the lateral compartment and hence a higher chances of tear. This may accelerate the progression of osteoarthritis on lateral compartment. We, therefore, carried out the case control study with a hypothesis that an HTO would accelerate the progression of osteoarthritis (OA) on lateral compartment in patients with complete discoid meniscus.

METHODS

The records of all patients with open wedge HTO from 2008 to 2012 were evaluated for complete lateral discoid meniscus. The patient who had a valgus HTO with or without partial meniscectomy for medial compartmental OA was included for this study. Cases to control were chosen to match age, body mass index (BMI), pre-operative osteoarthritis grade, and deformity angles in ratio 1:2. Patient's records were studied for demographic data, clinical examination records, and pre-operative knee functional scores and radiological scores and were compared with post-operative data.

RESULTS

Thirty-six patients out of 674 patients, who underwent an HTO, consisted of discoid meniscus group. 72 patients were chosen as control group. Four patients showed progression of OA on the lateral compartment in discoid group compared to none in control group. Although control groups showed a little bit better functional outcomes, there were no statistical differences between two groups (n.s.).

CONCLUSION

The high tibial osteotomy could result in accelerated lateral compartment osteoarthritis in patients with complete discoid meniscus, and the procedure should be used with caution in such patients.

LEVEL OF EVIDENCE

IV.

Factors affecting cartilage repair after medial opening-wedge high tibial osteotomy

PURPOSE

This study documented the healing potential of degenerated articular cartilage after opening-wedge valgus high tibial osteotomy (HTO) in patients with osteoarthritis of the knee. It was hypothesized that regeneration of articular cartilage is affected by several factors, including preoperative cartilage degeneration grade, difference between the medial femoral condyle (MFC) and the medial tibial condyle (MTC), and postoperative knee alignment.

METHODS

Medial opening-wedge valgus HTO was performed in 131 knees of 100 patients (mean age 66 ± 7.7 years). Initial arthroscopy was performed at the time of HTO, and a second-look arthroscopy was performed at the time of plate removal (20.8 ± 6.5 months after HTO). Status of articular cartilage was assessed according to the ICRS grade. Cartilage regeneration was also evaluated by the presence of newly formed cartilaginous tissue. All subjects were followed up postoperatively at 2 years for assessment of clinical and radiographic outcomes.

RESULTS

The number of subjects in ICRS grade 1/2/3/4 was significantly altered from 0/11/53/67 preoperatively to 14/21/56/40 postoperatively in the MFC (P < 0.05) and 0/12/62/57 preoperatively to 9/24/64/34 postoperatively in the MTC (P < 0.05). Newly formed cartilaginous tissue was found in 71 % of MFCs and 51 % of MTCs. Incidence of cartilage regeneration was significantly higher in lower BMI cases, MFC, preoperatively advanced ICRS grade and overcorrected knees. Age, gender and clinical outcomes did not affect cartilage regeneration.

CONCLUSION

Cartilage regeneration in degenerated articular cartilage is induced after opening-wedge valgus HTO, which is affected by BMI, the difference between the MFC and MTC, preoperative cartilage degeneration grade, and postoperative limb alignment. Therefore, patient selection by BMI rather than age, and surgical techniques maintaining valgus knee alignment should be considered for cartilage regeneration.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Post-operative deformation and extrusion of the discoid lateral meniscus following a partial meniscectomy with repair

PURPOSE

The purpose of this study was to investigate the morphology of the discoid lateral meniscus sequentially following a partial meniscectomy with repair using magnetic resonance imaging (MRI).

METHODS

Nine patients with a symptomatic discoid lateral meniscus with a peripheral tear were enrolled in this study, and a partial meniscectomy with repair was performed arthroscopically. An MRI examination was performed 2 weeks after surgery (before weight bearing was permitted) and again 6 months after surgery (when sporting activities could resume). The width, height and distance of the discoid lateral meniscus were measured. The distance was defined as the distance between the edges of the discoid lateral meniscus and the tibia.

RESULTS

The width of the anterior, middle and posterior segments significantly decreased from 2 weeks to 6 months after surgery. The height of the middle and posterior segments significantly increased from 2 weeks to 6 months after surgery, whereas the height of the anterior segment did not significantly change. The distance of the anterior, middle and posterior segments significantly decreased from 2 weeks to 6 months after surgery.

CONCLUSION

The discoid lateral meniscus exhibited deformation and extrusion from 2 weeks to 6 months after a partial meniscectomy with repair. Therefore, the function of load transmission might not be maintained appropriately after surgery.

LEVEL OF EVIDENCE

IV.