Revision of meniscal transplants: long-term clinical follow-up

Should the meniscal height be considered for preoperative sizing in meniscal transplantation?

PURPOSE AND HYPOTHESIS

In preoperative sizing for meniscal transplantation, most authors take into consideration the length and width of the original meniscus, but not its height. This study aimed at evaluating (1) whether the meniscal height is associated with the meniscal length and width, (2) whether the heights of the meniscal segments are associated with the individual's anthropometric data, (3) whether the heights of the meniscal segments are associated with each other in the same meniscus, and (4) the degree of symmetry of the meniscal dimensions between the right and left knees.

METHODS

In this cross-sectional, observational study, two independent radiologists measured the meniscal length, width and height in knee magnetic resonance imaging scans obtained from 25 patients with patello-femoral pain syndrome. Reproducibility of measurements was calculated with intraclass correlation coefficients. Associations between the anthropometric data and the meniscal measurements, the meniscal length and width versus height, and the heights of the meniscal segments in the same meniscus were examined with Pearson's correlation.

RESULTS

Inter-observer reliability was excellent (>0.8) for length and height and good (0.6-0.8) for width measurements. There was also excellent agreement (>0.8) for the length and width of the menisci in the right and left knees. The heights of the horns of the lateral meniscus showed good agreement (0.6-0.8), while the heights of the other meniscal segments had excellent agreement between the sides (>0.8). There were significant associations with generally low (r < 0.5) correlation between the heights of the meniscal segments and the lengths and widths of the menisci, between the meniscal height and anthropometric data, and between the heights of the meniscal segments in the same meniscus. Correlations between anthropometric data and meniscal length and width were generally high (r > 0.7).

CONCLUSIONS

There was excellent agreement between the meniscal dimensions of the right and left knees, and a weak association between the meniscal height with the meniscal width and length, between the height of the menisci with anthropometric data and between the heights of the segments in the same meniscus. The height of the meniscal segments may be a new variable in preoperative meniscal measurement.

The role of meniscal tissue in joint protection in early osteoarthritis

It is widely accepted that partial meniscectomy leads to early onset of osteoarthritis (OA). A strong correlation exists between the amount and location of the resected meniscus and the development of degenerative changes in the knee. On the other hand, osteoarthritic changes of the joint alter the structural and functional integrity of meniscal tissue. These alterations might additionally compromise the limited healing capacity of the meniscus. In young, active patients without cartilage damage, meniscus therapy including partial meniscectomy, meniscus suture, and meniscus replacement has proven beneficial effects in long-term studies. Even in an early osteoarthritic milieu, there is a relevant regenerative potential of the meniscus and the surrounding cartilage. This potential should be taken into account, and meniscal surgery can be performed with the correct timing and the proper indication even in the presence of early OA.

Meniscus transplantation

Understanding the structure and function of the meniscus is critical to understanding its role in overall knee joint function. Injury to, or removal of, meniscal tissue may be associated with articular cartilage wear, knee instability, and, ultimately, the progression of osteoarthritis. While every effort is made for preserving and/or repairing damaged meniscal tissue, in some cases, the meniscus is not amenable to repair after injury. For appropriately indicated patients with symptomatic meniscal deficiency, meniscus allograft transplantation is an excellent surgical solution aimed at reducing pain and improving function. Indications for meniscus allograft transplantation are limited, and concomitant procedures such as osteotomy for malalignment, ligamentous, and/or articular cartilage restoration may be necessary in order to ensure an optimal result following meniscus allograft transplantation. Surgical techniques for meniscus allograft transplantation are variable and include soft-tissue fixation versus bone plug fixation versus bone bridge fixation. Outcomes following meniscus allograft transplantation are generally good to excellent, though reoperation rates are relatively high. The purpose of this article is to provide a concise review of recently published data on meniscus allograft transplantation, with a focus on recent outcomes studies.

Meniscal allograft transplantation. Part 2: systematic review of transplant timing, outcomes, return to competition, associated procedures, and prevention of osteoarthritis

PURPOSE

To provide a systematic review of the literature regarding five topics in meniscal allograft transplantation (MAT): optimal timing for transplantation, outcomes, return to competition, associated procedures, and prevention of osteoarthritis.

METHODS

A systematic literature search was conducted using the PubMed (MEDLINE), ScienceDirect, and EBSCO-CINAHL databases. Articles were classified only in one topic, but information contained could be reported into other topics. Information was classified according to type of study (animal, in vitro human, and in vivo human) and level of evidence (for in vivo human studies). Specific inclusion criteria were determined for the outcomes and prevention of osteoarthritis topics.

RESULTS

Twenty-four studies were finally included: two optimal timing, seven outcomes, three return to competitive sport, 16 MAT and associated procedures, and 5 MAT and prevention of osteoarthritis (some studies were categorized in more than one topic). These studies corresponded to 2 animal studies and 31 in vivo human studies (1 level II, 1 level III, and 29 level IV).

CONCLUSIONS

The principal conclusions were as follows: (a) there is no evidence to support that MAT has to be performed at the same time or immediately after meniscectomy to prevent development of postmeniscectomy syndrome; (b) MAT successfully improves symptoms, function, and quality of life at 7-to-14 years of follow-up (level IV evidence); (c) the overall failure rate (need for knee arthroplasty) is 10-29% at long-term follow-up; (d) MAT allows return to same level of competition in 75-85% of patients at short- to mid-term follow-up (only three studies level IV evidence with small sample size); (e) associated cartilage procedures or anterior cruciate ligament reconstruction to MAT does not worsen the results; (f) MAT may prevent progression of cartilage damaged at long-term follow-up, but may not prevent degeneration in previously healthy cartilage.

LEVEL OF EVIDENCE

Systematic review of level II-IV studies, Level IV.