The degenerative effects of partial and total resection of the medial meniscus in dogs' knees.

An experimental effort to determine the degenerative effects in the articular cartilage of the knee joint caused by meniscectomy was performed by doing partial and total meniscectomies on the medial compartment of dogs' knees. Gross and microscopic pathological changes in teh articular cartilage were studied by sacrificing the dogs at intervals of three to ten months. Results indicated that meniscectomy is not a benign procedure, and the removal of a meniscus in itself can lead to degenerative changes in the knee joint. Partial meniscectomy leads to less severe degenerative changes with the degree of change directly related to the amount of meniscus removed. In total meniscectomies when meniscus regeneration occurred, the cartilage surfaces where the meniscus had regenerated were protected. The degree of degenerative change was directly related to the amount of fibrocartilage that remained absent. Therefore, the knee menisci function to protect the articular cartilages from degenerative damages, but the exact mechanism of this is unknown.     

Clinical aspects of the detection of early arthrosis. Degenerative changes of the menisci of the knee joint

In a series of 420 persons the knee and hip joints were examined anamnestically and clinically. From this series, 146 persons were selected for further examination of one knee joint by means of magnetic resonance imaging (MRI) on a 1.5 Tesla Magnetom; there was a wide range of indications. Only four MRIs showed no pathological findings in the cruciate ligaments, cartilage surfaces, or menisci. Fifty-one menisci showed grade 3 degenerative changes. In 29 cases (57%), isolated horizontal tears were found, in 1 case (2%) an isolated vertical tear, and in 3 cases (6%) combined horizontal and vertical tears. The correlation of the degenerative changes in the medial meniscus and age was significant (P = 0.01). There was no correlation between the degenerative changes of the medial meniscus and femoral or tibial changes of the cartilage. In this series, there was no significant connection between degenerative changes of the medial meniscus and the previously accepted clinical symptomatology.     

Management of discoid lateral meniscus tears: Observations in 34 knees

Purpose: The goal of this study was to evaluate arthroscopic partial resection of discoid lateral meniscus tears with an emphasis on radiographic evidence of degenerative changes after this procedure. Type of Study: Retrospective clinical study. Methods: Of 41 patients with an arthroscopic diagnosis of discoid meniscus over an 8-year period, 34 symptomatic lateral discoid meniscus tears in 33 patients were analyzed at an average follow-up of 5.6 years. The average age at operation was 19.8 years and most patients had vague and intermittent symptoms that caused delay in clinical diagnosis. Results: Eight patients were lost to follow-up and were excluded from the study. Magnetic resonance imaging, performed in 12 cases, and arthroscopy in all of these patients provided the precise diagnosis. All of the knees with symptomatic torn discoid menisci underwent arthroscopic partial meniscectomy. Only 1 Watanabe Wrisberg ligament type of discoid meniscus with posterior instability was totally meniscected. Based on Ikeuchi's grading, 39% of the knees had an excellent result, 46% had a good result, and 15% had a fair result; none of the results was poor. Conclusions: At an average 5-year follow-up, partial meniscectomy in patients with a Watanabe complete or incomplete discoid meniscus showed 85% good or excellent clinical results. However, a significant percentage of patients show femoral condyle flattening on radiography.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 19, No 4 (April), 2003: pp 346–352     

Arthroscopic management of degenerative meniscus tears in patients with degenerative arthritis

Frequently, meniscal pathology accompanies degenerative changes affecting the articular surface of the knee. The attritional changes in the meniscus lead to fragmentation of the meniscus and a variety of tears, usually of the posterior horn of the medial meniscus. A prospective study of the results of arthroscopic partial meniscectomy in the presence of at least Outerbridge Grade III chondromalacia of the accompanying joint surface was performed between 1980 and 1984. Eighty-seven knees in 84 patients were studied. The mean age was 62 (29-84) years. The right knee was involved in 44 patients, and 47 were men. Preoperative radiographs demonstrated osteoarthritis in 53 patients. The medial meniscus was involved in 82, while the lateral meniscus was affected in nine knees. Four knees had involvement of both menisci. In 72 knees, the most frequent lesion was a tear of the posterior horn of the medial meniscus. The most frequent configuration of the tears was a flap in 42. The morbidity was small with the use of ambulatory aids being 10 +/- 13 (mean +/- SD) days. Subsequent surgery was performed on six knees consisting of two total knee arthroplasties, two upper-tibial osteotomies, one repeat arthroscopic meniscectomy, and one popliteal cyst excision. Two patients had poor results related to progression of their arthritis and one developed osteonecrosis. Five patients were unchanged from their preoperative status. Subchondral sclerosis or osteophytes on the preoperative radiographs correlated with 72% compared to 90% satisfactory results in the absence of these findings (p less than 0.03). Complications consisted of superficial thrombophlebitis in three, hemarthrosis in one, and superficial infection in one patient.(ABSTRACT TRUNCATED AT 250 WORDS)     

Arthroscopic surgery of the knee in local anaesthesia

Summary Arthroscopy of the knee joint was performed in 356 consecutive outpatients in local anaesthesia and without premedication. A continuous pressure-irrigation system was used with 0.2% lidocaine chloride solution in the irrigation fluid, following administration of 5–7 ml prilocaine with epinephrine in each portal. All patients had clinical symptoms of internal derangement of the knee, such as meniscal, cruciate ligament injury or osteoarthritis. Associated intra-articular pathology was registered. Intra-articular surgery was performed in 228 cases. This included partial or subtotal meniscectomy in 207 cases and meniscus suture in 3 cases. In 18 of 228 cases (8%) the operative procedure had to be terminated due to patient discomfort. Of the meniscal injuries 84% were medial and 16% lateral. The age distribution of the medial meniscus tears was as follows: bucket handles 33 ± 9 years; flap tears 42 ± 10 years and degenerative tears 53 ± 10 years. For the lateral meniscus the age distribution was: bucket handles 34 ± 9 years, cleavage and radiating tears 37.5 ± 12 years, flap tears 29 ± 7 years, peripheral tears 32 ± 9 years and degenerative tears 48 ± 11 years. Osteoarthritis was observed in 52% of all medial degenerative tears, whereas a low frequency was found in the remaining tears. The majority of patients tolerated the procedure well. In summary, 64% of the consecutive arthroscopies were operative, including 3 meniscal sutures. Only 8% of these procedures had to be abandoned due to patient discomfort. Thus, arthroscopic surgery in local anaesthesia with no premedication is an efficient and well-tolerated method in outpatient practice.     

半月板撕裂和切除对前交叉韧带断裂力学稳定性的影响

目的探讨半月板对前交叉韧带断裂及重建术后胫骨前向稳定性的影响。 方法收集2017年1月至2018年10月期间前交叉韧带重建患者,排除前交叉韧带部分断裂和多发韧带损伤病例。所有不稳定半月板撕裂均行半月板部分切除术,根据半月板损伤部位及程度进行分组。采用KT-1000测量术前、术后3个月和6个月的胫骨前平移量(ATT)。组间对照采用独立样本t检验。 结果共纳入158例前交叉韧带断裂患者,其中半月板正常组61例,内侧半月板后角撕裂组49例(19例为撕脱<总宽度40%;30例为撕脱≥总宽度40%);外侧半月板撕裂组35例(12例为撕脱<总宽度40%;23例为撕脱≥总宽度40%);内侧半月板前角或体部撕裂组13例(6例为撕脱<总宽度40%;7例为撕脱≥总宽度40%)。术前内侧半月板后角撕裂≥总宽度40%患者的胫骨前平移量较半月板正常患者明显增加,差异有统计学意义(t＝12.141,P<0.01)。术后3个月及6个月,各个半月板撕裂组的ATT值与半月板正常患者相比均无差异(P >0.05)。 结论内侧半月板后角撕裂与前交叉韧带断裂可增加膝关节的不稳定性,半月板部分切除术对前交叉韧带重建术后患者的膝关节稳定性无影响。     

Arthroscopic meniscectomy in the anterior cruciate ligament-deficient knee

Patients with injury to the anterior cruciate ligament (ACL) frequently develop tears of the menisci. Removal of the meniscus, while relieving some complaints, may increase the patient's instability. To evaluate our success and quantify the reasons for failure, we evaluated 48 patients who underwent arthroscopic partial meniscectomy from 1979 to 1982. Patients were evaluated as to their subjective complaints, scored on a 100-point knee evaluation, and evaluated with standing x-rays. In addition, measurement using the KT-1000 knee arthrometer was made to assess the degree of tibial translation. Follow-up averaged 32 months, with a range of 24-50. At followup, 29 patients (60%) were judged to be clinical successes with resolution of their complaints and no aggravation of their instability. Nineteen patients (40%) were judged to be clinical failures in that their complaints persisted (14 patients) or ACL reconstruction was required (5 patients). Eight patients noted some increase in their instability, and three required a repeat meniscectomy. Arthroscopic partial meniscectomy can be a useful procedure in some patients with injury to the ACL. Patients more likely to do well are those with a torn medial meniscus with a chief complaint of locking. Examination would demonstrate a mild pivot shift, absence of generalized ligamentous laxity, and an anterior tibial translation difference of less than 5 mm.     

Fifteen-year follow-up of arthroscopic partial meniscectomy

From an original pool of 283 patients, 146 patients who had undergone arthroscopic partial meniscectomy an average of 14.7 years before were followed-up. Lysholm score, Tegner activity level, satisfaction index on a scale of 1 to 10, and standing anteroposterior and flexion weight-bearing radiographs of both knees, were obtained. A physical examination was performed on each knee emphasizing motion, swelling, and ligament evaluation. Radiographs were graded for degenerative changes for each knee. Each knee joint space was also measured in millimeters and compared, operative knee with unoperated knee. The unoperated knee had no injuries or surgeries and was used as a control. Patients were 83% male and 17% female; 78% had undergone medial meniscectomies, 19% lateral, and 3% both. There were 88% good and excellent results in anterior cruciate liagment—stable knees. The radiographic grade side-to-side difference showed the operative knee to be only a 0.23 grade worse than the nonoperative knee. Age at the time of meniscectomy was not found to be a factor. Male patients had better radiographic results than female patients, but not better functional scores. Medial meniscus and lateral meniscus results were not significantly different. Knees with a femoral-tibial anatomic alignment of >0° valgus compared with ≤0° and that had undergone medial meniscectomy had significantly better radiographic results. Patients with anterior cruciate ligament tears and meniscectomy did significantly poorer than stable knees with meniscectomy in regards to radiographic grade change, Lysholm, satisfaction index, Tegner level, and medial joint space narrowing.     

Meniscectomy

To review the meniscus from a historical perspective especially on surgical management and general guidelines for arthroscopic meniscectomy procedures for various types of meniscal tears. We searched MEDLINE and PubMed for the years of 1980-2010 using the terms meniscus, meniscal repair, menisectomy, and arthroscopy. Orthopedic surgeons frequently encounter patients with pain or functional impairment of the knee joint and repair or resection of the injured meniscus is one of the most common orthopedic operative procedures. The object of meniscal surgery is to reduce pain, restore functional meniscus and prevent the development of degenerative osteoarthritis in the involved knee. Historically, total meniscectomy was a common procedure performed for meniscus tear symptoms. However, it has been reported that total meniscectomy has deleterious effects on the knee. In the past, the menisci were thought as a functionless remnant tissue. Currently, it is known that the meniscus is an important structure for knee joint function. Menisci provide several vital functions including mechanical support, localized pressure distribution, and lubrication to the knee joint. It is widely accepted that the function of the meniscus can be preserved through minimal excision. An arthroscopic partial meniscectomy preserving more of the meniscus is preferred over total meniscectomy. In recent decades, this shift toward arthroscopic partial meniscectomy has led to the development of new surgical techniques.     

Ligament repair in the knee with preservation of the meniscus

In early surgical repair of forty acute ruptures of the medial ligament of the knee in patients sixteen to twenty-four years old, the meniscus was resutured when it was avulsed from the bone and was excised only when there was central disruption (three knees). Follow-up of one to six years in thirty-six patients whose menisci were preserved showed that thirty-three had no limitations due to knee impairment. Twenty-six patients were re-examined; sixteen had no medial instability and twenty-one had no anterior rotatory instability. We concluded that in the absence of significant advantage from meniscectomy, an intact meniscus should not be removed.     

Effects of radial tears and partial meniscectomy of lateral meniscus on the knee joint mechanics during the stance phase of the gait cycle—A 3D finite element study

The purpose of the current study was to evaluate influences of radial tears and partial meniscectomy of lateral meniscus on the knee joint mechanics during normal walking by using computational modeling. A 3D geometry of a knee joint of a healthy patient was obtained from our previous study, whereas the data of normal walking were taken from the literature. Cartilage tissue was modeled as a fibril reinforced poroviscoelastic material, whereas meniscal tissue was modeled as a transverse isotropic elastic material. The realistic gait cycle data were implemented into the computational model and the effects of radial tears and partial meniscectemy of lateral meniscus on the knee joint mechanics were simulated. Middle, posterior, and anterior radial tears in lateral meniscus increased stresses by 300%, 430%, and 1530%, respectively, at the ends of tears compared to corresponding areas in the model with intact lateral meniscus. Meniscus tears did not alter stresses and strains at the tibial cartilage surface, whereas partial meniscectomy increased contact pressures, stresses, strains and pore pressures in the tibial cartilage by 50%, 44%, 21%, and 43%, respectively. Increased stresses and strains were observed primarily during the first ～50% of the stance phase of the gait cycle. The present study suggests that anterior radial tear causes the highest risk for the development of total meniscal rupture, whereas partial meniscectomy increases the risk for the development of OA in lateral tibial cartilage. Highest risks for meniscus and cartilage failures are suggested to occur during the loading response and mid‐stance of the gait cycle. In the future, the present modeling may be further developed to offer a clinical tool for aid in decision making of clinical interventions for patients with knee joint injuries. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1208–1217, 2013     

Microvasculature of the human medial meniscus: operative findings.

The purpose of our study was to weigh the probability of a successful meniscus repair on the basis of the microvasculature of the human medial meniscus. In a series of 105 patients who underwent an anterior cruciate ligament reconstruction between January 1985 and December 1986, we chose the 40 patients who had a subtotal medial meniscectomy (38%) to study the microvasculature of the human medial meniscus adequately; the other patients had either an intact meniscus (23%), a meniscus repair (29%), or an already removed meniscus (10%). Forty medial menisci, from 40 male patients with an average age of 27 years, having an anterolateral and/or anteromedial chronic knee laxity and an associated meniscal pathology, were subdivided into two groups: (a) 20 tears restricted to the posterior horn, and (b) 20 bucket-handle tears observed under light microscopy. Meaningful capillary plexuses penetrating into the meniscal stroma were found in 18 of 40 menisci (45%). They were easier to identify in posterior horn tears (55%) than in bucket-handle tears (35%), and were found especially in younger patients (22 years on the average). Therefore, we encourage meniscus repairs even in chronic tears, particularly in younger patients and in posterior-horn tears.     

Meniscus Tears: Treatment in the Stable and Unstable Knee

Basic science research and follow-up studies after meniscectomy have provided convincing evidence of the importance of preservation of the meniscus in decreasing the risk of late degenerative changes. Whether in a stable or an unstable knee, if a meniscus tear cannot be repaired, a conservative partial meniscectomy should be undertaken to preserve as much meniscal tissue as possible. When feasible, repair should be carried out in young patients with an isolated meniscus tear, despite healing rates that are significantly lower than those obtained when meniscus repair is done with anterior cruciate ligament (ACL) reconstruction. The incidence of successful healing is inversely related to the rim width and tear length. In general, meniscus repair should be limited to patients under 50 years of age. Vertical longitudinal tears, including bucket-handle tears, are most amenable to repair. Some radial split tears can be repaired. In an ACL-deficient knee, meniscus repair is more prone to failure if not performed in conjunction with an ACL reconstruction, and is not recommended. Meniscal allograft surgery is investigational but may hold promise for selected patients.     

Is repeated repair of the meniscus worthwhile?

Meniscal injuries are one of the most commonly encountered problems by orthopaedic surgeons. It is well established that meniscectomy will result in increased joint surface contact forces and the predictable progression of arthritis. The management of meniscal tears has evolved and current evidence would suggest that every attempt should be made to repair meniscal tears when appropriate. The reported success rate of meniscal repair is encouraging, but relatively little is known about the outcome of repeated repair of a re-torn meniscus. This review presents an illustrative case of a recurrent lateral meniscal tear in a young female, that has required surgical repair on three occasions over a fourteen year period. Despite recurrent tears of her lateral meniscus, the patient was symptom-free in the intervening periods and at her latest operation, her articular cartilage showed minimal evidence of chondral damage. Longer-term follow-up is required to determine whether repair of a re-torn meniscus prevents the progression of degenerative changes within the knee joint that is associated with meniscectomy.     

Meniscal tearing after ACL reconstruction

The knees of 72 patients with unilateral anterior-cruciate- ligament (ACL) injury were analyzed before ACL reconstruction as well as by follow-up arthroscopy on the day of staple removal. At ACL reconstruction 31 lateral menisci and 40 medial menisci were found to be normal. 28 lateral menisci and 24 medial menisci were treated surgically, while 13 lateral menisci and 8 medial menisci with small or incomplete meniscal tearing were not treated. At follow-up arthroscopy there were 3 new cases of lateral meniscal tearing and 3 new cases of medial meniscal tearing in the groups diagnosed as normal prior to surgery. Two of the 13 cases with small or incomplete lateral meniscal tearing required resection, 8 healed and the other 3 demonstrated no progressive change. Four of the 8 cases with small or incomplete medial meniscal tears healed, 3 exhibited no progressive change and one required surgical treatment. There was no correlation between meniscal tearing and knee instability as indicated by a positive Lachman test or a positive pivot shift sign. The results of the present study indicate that ACL reconstruction prevents progressive changes in meniscal tears and will prevent secondary osteoarthritis, and that some small tears of the lateral meniscus require no surgical treatment.     

Diagnostics of degenerative meniscal tears at 3-Tesla MRI compared to arthroscopy as reference standard

Introduction The goal of this study was to evaluate the diagnostic performance of 3-Tesla MRI for the assessment of degenerative meniscal tears in clinical practice. Materials and methods In patients with chronic knee pain, a negative history of acute trauma and a mean age of 52 years, 3-Tesla MRI were performed a few days prior to arthroscopy. In 86 menisci, diagnostic values of 3-Tesla MRI for the detection of degenerative tears were evaluated using arthroscopy as reference standard. The MRI classification, for meniscus diagnostics, described by Crues was used. Results At arthroscopy, all tears identified (19 horizontal, 7 complex, 3 radial) were degenerative as confirmed by histological examination. MRI grade II lesions had a prevalence of 24% and a rate of 24% of missed tears, whereas grade I lesions were not associated with a torn meniscus at arthroscopy. For meniscal tears, (grade III) sensitivity and specificity of 3-Telsa MRI was 79 and 95% for both menisci, 86 and 100% for the medial meniscus, and 57 and 92% for the lateral meniscus. The best diagnostic performance was found for complex tears, horizontal tears showed relatively good results, poor results were documented for radial tears. Conclusion For the medial meniscus, where horizontal and complex tears were more prevalent, 3-Tesla MRI shows a higher accuracy than for the lateral meniscus. Particularly with regard to the medial meniscus, 3-Tesla MRI could be effectively used when a degenerative tear is suspected. Nevertheless, in regard to a remarkable number of false positive and false negative findings the diagnostic value of a 3-Tesla MRI investigation should not be overestimated.     

Lateral meniscal variant with absence of the posterior coronary ligament.

We reviewed the cases of 3468 patients who had had arthroscopy of the knee between January 1976 and December 1988. Twenty-six patients (0.8 per cent) had a partial or a complete discoid lateral meniscus, and seven (0.2 per cent) had the Wrisberg-variant-type lateral meniscus. Of the seven patients, six had operative stabilization of the meniscus and one had a partial lateral meniscectomy because of an irreparable complex tear. Subjective, objective, and radiographic evaluations were performed on the patients who had had stabilization of the meniscus. According to the scale of Tegner and Lysholm, the result was excellent in four patients, good in one, and fair in one. None of the six patients had a tear of the sutured meniscus after an average follow-up of thirty-two months (range, twenty-four to forty months). Two patients had progressive symptoms attributable to osteoarthrosis, but the changes in the articular cartilage had been present at the time of the index procedure. None of the seven Wrisberg-variant-type menisci demonstrated a true discoid shape of the meniscus. We therefore classified this lesion as a lateral meniscal variant with absence of the posterior coronary ligament.     

Kombinierte Verletzung des Innen- und Außenmeniskus und des vorderen Kreuzbandes

THE PROBLEM: Combined injury of the medial and lateral meniscus and the anterior cruciate ligament. THE SOLUTION: One-stage arthroscopic treatment of all injuries. Repair of the bucket-handle tears with sutures and arrow-shaped implants. SURGICAL TECHNIQUE: Arthroscopy of the knee joint, repositioning of the buckethandle tears of the medial and lateral menisci. Evaluation of the stability of the menisci without sutures, insertion of horizontal and vertical sutures through the menisci in inside-out technique, refixation of the posterior horns with arrow-shaped meniscus implants. Reconstruction of the anterior cruciate ligament with a patellar tendon transplant. Knotting of the suture loops through the menisci directly onto the capsule. RESULT: Stable knee joint capable of load bearing and without signs of irritation after 12 weeks with a range of motion of 0/0/130 degrees. Slight muscle deficit in the right thigh.     

Simple arthroscopic partial meniscectomy associated with anterior cruciate-deficient knees

Twenty-five patients with combined tears of the meniscus and anterior cruciate ligament in the same knee were evaluated for the results of a simple arthroscopic meniscectomy that preserved the meniscal rim. These patients, classified as "recreational athletes," were analyzed to determine their postoperative functional capabilities. Using the presence or absence of the pivot shift sign as the most important indicator of functional capability, we found that partial meniscectomy was effective in allowing patients to regain a high degree of normal functional ability and in permitting forward motion activities. However, all patients were left with an anterior cruciate-deficient knee that caused laxity in the anterior plane and frequently in the rotatory plane. Rotatory laxity markedly limits activities, and those patients unable to adjust to their instability are considering further surgery.