Effect Of Medial Meniscectomy Research Articles

MR T1ρ and T2 of meniscus six months and one year after acute anterior cruciate ligament injury

s / Osteoarthritis and Cartilage 23 (2015) A82eA416 A223 354 MR T1r AND T2 OF MENISCUS SIX MONTHS AND ONE YEAR AFTER ACUTE ANTERIOR CRUCIATE LIGAMENT INJURY A. Wang, F. Su, V. Pedoia, M. Kretzschmar, L. Nardo, T.M. Link, C.B. Ma, X. Li. Univ. of California, San Francisco, San Francisco, CA, USA Purpose: Acute anterior cruciate ligament (ACL) injury, a high-risk factor for post-traumatic osteoarthritis, is often concomitant with meniscal lesions and tears. In our previous cross-sectional study, we found that acute ACL injuries were associated with significantly elevated meniscal T1r and T2 values compared to healthy knees, even in menisci without morphological signs of damage. The goal of this longitudinal study was to evaluate intermediate-term changes in meniscal T1r and T2 quantification in ACL-injured patients six months and one year after ACL reconstruction and to compare these changes to baseline results. Methods: Using a 3T MR scanner, a closed cohort of 39 patients (age 1⁄4 29.4 ± 7.5 years; 16 females) with acute ACL injuries was scanned at an average of 8.4 ± 6.4 weeks post-injury and prior to ACL reconstruction. After ACL reconstruction, follow-up scans of ACL-injured knees were completed at six months and one year after baseline scan. Subjects were categorized by no lateral meniscectomy (n 1⁄4 32) and partial lateral meniscectomy (n 1⁄4 7). Effects of medial meniscectomy were not evaluated due to small sample size (n 1⁄4 2). Imaging protocol included sagittal T2-weighted 3D fast spin-echo (CUBE) images [repetition time (TR)/echo time (TE) 1⁄4 1500/25 ms, field of view (FOV)1⁄4 16 cm, matrix1⁄4 384 x 384, slice thickness1⁄4 1mm, echo train length 1⁄4 50, bandwidth 1⁄4 50 kHz, number of excitations 1⁄4 0.5] and sagittal 3D T1r and T2 quantification sequences [TR/TE 1⁄4 9 ms/min full, FOV1⁄4 14 cm, matrix1⁄4 256 x 128, slice thickness1⁄4 4mm, Views Per Segment 1⁄4 64, time of recovery 1⁄4 1.2 s, spin-lock frequency 1⁄4 500 Hz, ARC phase AF1⁄4 2. TSL1⁄4 0/10/40/80 ms for T1r, and preparation TE1⁄4 0/ 13.7/27.3/54.7 ms for T2]. Menisci were segmented using CUBE images into four sub-compartments: anterior horn of the lateral/medial meniscus (AHLAT/AHMED) and the posterior horn of the lateral/medial meniscus (PHLAT/PHMED). These regions of interest (ROI) were overlaid onto T1r and T2 maps, andmean T1r and T2 values were calculated for each ROI. Paired t-tests were performed when comparing the same cohort at different time points, and unpaired t-tests were performed when comparing patients who had a partial meniscectomy and patients who did not have a meniscectomy. An alpha of less than 0.05 was considered significant. Results: In ACL-injured knees without meniscectomy, T1r values increased significantly from baseline to six months in the AHLAT, AHMED, and PHMED (all p r > -0.46; p r > -0.30; p<0.005). Intraclass correlation coefficients ranged between 0.95-1.00 for the DCE-MRI variables and 0.80-1.00 for the static MRI variables. Conclusions: The results confirm an association between pain and synovitis assessed on both DCEand CE-MRI in obese patients with knee OA. The whole-knee synovitis score on CE-MRI and most of the DCE-MRI variables were also significantly associated with the remaining KOOS items. DCE-MRI analyses were robust and highly reproducible and have the potential to be used to further investigate the role of inflammation and perfusion in knee OA, in a similar way it has been used in inflammatory joint diseases.

Patterns of Meniscal Damage Associated with Acute ACL Rupture

Patterns of Meniscal Damage Associated with Acute ACL Rupture

Current concepts in meniscus surgery: resection to replacement

More recently, increasing attention has been turned toward the preservation and restoration of the medial and lateral menisci of the knee. The literature is replete with studies that cite the important biomechanical roles that the menisci play in shock absorption and load distribution across the knee in addition to contributing to stability, joint congruence, articular cartilage nutrition, lubrication, and proprioception. 1 Kettlekamp D. Jacobs A. Tibiofemoral contact area Determination and implications. J Bone Joint Surg Am. 1972; 54: 349-356 PubMed Google Scholar , 2 Walker P. Erkman M. The role of the menisci in force transmission across the knee. Clin Orthop. 1975; 109: 184-192 Crossref PubMed Scopus (814) Google Scholar , 3 Levy M. Torzilli P. Warren R. The effect of medial meniscectomy on anterior-posterior motion of the knee. J Bone Joint Surg Am. 1982; 64: 883-888 PubMed Google Scholar , 4 Radin E. de Lamotte F. Maquet P. The role of the menisci in the distribution of stress in the knee. Clin Orthop. 1984; 185: 290-294 PubMed Google Scholar , 5 Shoemaker S. Markolf K. The role of the meniscus in the anterior-posterior stability of the loaded anterior cruciate deficient knee Effects of partial versus total excision. J Bone Joint Surg Am. 1986; 68: 71-79 PubMed Google Scholar , 6 Beaupre A. Choukroun R. Guidouin R. Knee menisci Correlation between microstructure and biomechanics. Clin Orthop. 1986; 208: 72-75 PubMed Google Scholar , 7 Baratz M. Fu F. Mengato R. Meniscal tears The effect of meniscectomy and of repair on intraarticular contact areas and stress in the human knee. A preliminary report. Am J Sports Med. 1986; 14: 270-275 Crossref PubMed Scopus (647) Google Scholar Published data supports that meniscal attrition after subtotal meniscectomy could be associated with degenerative processes in adjacent articular cartilage surfaces. 7 Baratz M. Fu F. Mengato R. Meniscal tears The effect of meniscectomy and of repair on intraarticular contact areas and stress in the human knee. A preliminary report. Am J Sports Med. 1986; 14: 270-275 Crossref PubMed Scopus (647) Google Scholar , 8 Johnson R. Kettelkamp D. Clark W. Factors effecting late results after meniscectomy. J Bone Joint Surg Am. 1974; 56: 719-729 PubMed Google Scholar , 9 Jorgensen U. Holm S. Lauridsen F. Long term follow-up of meniscectomy in athletes A prospective longitudinal study. J Bone Joint Surg Br. 1987; 69: 80-83 PubMed Google Scholar , 10 Bolano L. Grana W. Isolated arthroscopic partial meniscectomy. Functional radiographic evaluation at five years. Am J Sports Med. 1993; 21: 432-437 Crossref PubMed Scopus (152) Google Scholar , 11 Osti L. Liu S. Raskin A. Merlo F. Bocchi L. Partial lateral meniscectomy in athletes. Arthroscopy. 1994; 10: 424-430 Abstract Full Text PDF PubMed Scopus (50) Google Scholar , 12 Hede A. Larsen E. Sandberg H. Partial versus total meniscectomy. J Bone Joint Surg Br. 1992; 74: 118-121 PubMed Google Scholar , 13 Anderson-Molina H. Karlsson H. Rockborn P. Arthroscopic partial and total meniscectomy Long-term follow-up study with matched controls. Arthroscopy. 2002; 18: 183-189 Abstract Full Text Full Text PDF PubMed Scopus (206) Google Scholar , 14 Schimmer R. Brulhart K. Duff C. Glinz W. Arthroscopic partial meniscectomy A 12-year follow-up and two-step evaluation of the long-term course. Arthroscopy. 1998; 14: 136-142 Abstract Full Text PDF PubMed Scopus (118) Google Scholar Despite this body of work, arthroscopic meniscectomy remains one of the most commonly performed orthopaedic procedures. The development of an increasingly more sophisticated and scientific understanding and approach to knee problems and, in particular, the natural history of the meniscectomized knee has raised concern for the risk of late degenerative arthrosis. Multiple other factors have continued to heighten interest in meniscal surgery, including the trend in our society for all age groups to place greater emphasis on fitness and remaining active. This has raised the demand for normalizing knee function, not only after injury, but also at extended follow up. Patients, the media, and clinicians alike all focus more attention on the treatment as well as the prevention of osteoarthritis. Furthermore, as more advanced technical capability has evolved as far as knee surgery is concerned, there is an increasing tendency to carry out more comprehensive arthroscopic and reconstructive surgical methods. Expanding surgical indications and demand now exists for anterior cruciate ligament (ACL) reconstruction, articular cartilage biologic resurfacing, and correction of axial malalignment as well as meniscal preservation or replacement surgery. Interest in the meniscus continues to remain in the forefront of basic scientific work, clinical study, and novel technology development. The purpose of this publication is to review the current and potential future approaches to meniscal pathology, including decision-making and indications for meniscal resection versus repair, and to report on several of newest devices and methods for repairing meniscal tears and replacing and transplanting meniscal tissue.

In vitro load transmission in the canine knee: the effect of medial meniscectomy and varus rotation.

The purpose of this study was to determine the in vitro load-transmission characteristics of the canine knee, paying particular attention to the positioning effect of the meniscus in the coronal plane. The intact joint was first loaded and then tested under two different loading conditions after a complete medial meniscectomy. The first set of test conditions attempted to simulate those used by previous investigators, by ignoring the spacer effect of the meniscus. The second set of tests were carried out following varus rotation of the joint (to account for the loss of the meniscal spacer) to assure initial contact in both tibiofemoral compartments at the start of test cycle. It is presumed that this varus realignment occurs during weight bearing following meniscectomy in vivo. As in previous studies, the joints experienced slightly larger displacements (although not statistically significant) and had lower stiffness values following medial meniscectomy than when intact. However, following varus realignment of the joint after meniscectomy, the displacement was markedly smaller (-35% to -49%; P < 0.01) and the structural stiffness was much greater (47-123%; P < 0.05) over the range of forces analyzed, compared with the intact joint. The ratio of dissipated to input energy was 42% for the intact joint, and increased following meniscectomy to 54% (P < 0.05) with realignment and 55% (P < 0.05) without realignment. Measured contact area decreased by 17% (P < 0.05) following meniscectomy alone, and by 12% (P < 0.05) following meniscectomy with realignment.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of medial meniscectomy and coronal plane angulation on in vitro load transmission in the canine stifle joint.

The purpose of this study was to determine the in vitro load transmission characteristics of the canine stifle joint, paying particular attention to the positioning effect of the meniscus in the coronal plane. The intact joint was first loaded, and then tested under two different loading conditions after a complete medial meniscectomy. The first set of test conditions attempted to simulate those used by previous investigators, by ignoring the spacer effect of the meniscus and not repositioning the joint after its removal. The second set of tests was carried out after the joint was repositioned in the coronal plane to allow initial contact to occur in both tibiofemoral compartments. It is presumed that this occurs subsequent to a meniscectomy in vivo, following the application of any weight-bearing load. As with previous investigators, it was found that after meniscectomy the joints produced slightly larger displacements and lower stiffnesses than when intact (no significant differences from intact). However, repositioning the meniscectomized joint produced markedly smaller displacements (35-49%, p less than 0.01) and greater stiffnesses (47-123%, p less than 0.05) over the range of forces analyzed, compared with the intact joint. The ratio of dissipated to input energy was 42% for the intact joint, and rose following meniscectomy to 54% (p less than 0.05) with repositioning and 55% (p less than 0.05) without repositioning. Measured contact area decreased by 17% (p less than 0.05) following meniscectomy alone, and by 12% (p less than 0.05) following meniscectomy with repositioning. Since repositioning of the joint subsequent to meniscectomy (accounting for the loss of the meniscal spacer) resulted in an increase in structural stiffness, it was concluded that the medial meniscus decreases the structural stiffness of the intact stifle joint. In addition, the meniscus has a role in elastic energy storage and increasing contact area. This study is intended to serve as a baseline comparison for future in vivo studies on meniscectomy, meniscal repair, and meniscal replacement, in addition to more fully elucidating the mechanism of load transmission. A model is presented to explain both the decrease in stiffness after meniscectomy without repositioning and the increase in stiffness after meniscectomy with repositioning, employing linear springs of unequal length and different stiffnesses. After removal of the softer meniscal element and allowing joint approximation to occur, loading of the stiffer articular element results in an initially stiffer preparation.

The effect of medial meniscectomy on strain distribution in the proximal part of the tibia.

The tibiae of five fresh adult human cadaver legs (amputated proximal to the knee) were instrumented with twenty-five strain-gauge rosettes and were tested in axial compression, simulating single-limb stance, at loads of as much as 2450 newtons. We compared the status of the normal knee, with menisci intact, with the status of the same knee after partial or total medial meniscectomy. The resultant changes in strain on the cortical bone of the tibia indicated that medial meniscectomy caused reduced compressive strains on the whole of the lateral aspect of the tibia, while on the medial aspect compressive strains were increased at all levels beyond seventy millimeters distal to the joint-line; however, within fifty millimeters of the joint-line on the medial aspect, there was a significant reduction of compressive strains.

The effect of medial meniscectomy on anterior-posterior motion of the knee.

We used an in vitro knee-testing apparatus to measure anterior-posterior displacement of the tibia on the femur and the accompanying tibial rotation in response to an applied anterior-posterior force. Testing was performed on nine intact knees, on five knees after medial meniscectomy, on three knees after isolated section of the anterior cruciate ligament, and on eight knees after both excision of the medial meniscus and section of the anterior cruciate ligament. The induced anterior-posterior displacement and the coupled rotation were unaffected by meniscectomy. Isolated section of the anterior cruciate ligament allowed a significant (p less than 0.05) increase in anterior displacement but had no effect on posterior displacement. The coupled internal rotation associated with anterior displacement was lost after section of the anterior cruciate ligament. Excision of the medial meniscus and section of the anterior cruciate ligament allowed significantly (p less than 0.05) greater increases in anterior displacement than those already increased by isolated section of the anterior cruciate ligament.

Effects of medial meniscectomy in patients older than forty years.

Forty-nine of the sixty-five consecutive patients who were more than forty years old when medial meniscectomy was performed returned for follow-up evaluation one to twelve years postoperatively. Pain was present in 62.2 per cent of the patients with so-called degenerative tears and in 75 per cent of those with so-called traumatic tears. The medial joint space was significantly thinner in the patients with degenerative tears than in those with traumatic tears. The roentgenographic findings of osteoarthritis were significantly more severe on the side operated on. The femorotibial angle was always in relatively more varus angulation on the involved side (mean, 5.3 degrees) than on the uninvolved side.