A critical analysis of cartilage repair

Return to sports after autogenous osteochondral mosaicplasty of the femoral condyles: 25 cases at a mean follow-up of 9 years

INTRODUCTION

Autogenous osteochondral mosaicplasty is the most common cartilage restoration technique in standard clinical practice. The purpose of this study was to evaluate the return to sports 9 years after mosaicplasty of the femoral condyles.

HYPOTHESIS

The long-term results of an osteochondral autograft show that patients can regain their pre-injury activity level.

MATERIAL AND METHODS

This study is based on a series of 25 patients with a mean age of 28.9 years (range, 16-44 years) who had stage 3 or 4 chondral lesions of the femoral condyles (according to the ICRS or ICRS-OCD scores). The origin of the lesion was osteochondritis dissecans (13 knees), osteochondral fracture sequelae (ten knees), or aseptic osteonecrosis (two knees). The average size of the lesion was 2.11 ± 0.9 cm(2). Ten patients (40%) had an associated procedure during the osteochondral autograft. The patients were assessed clinically (IKDC and Lysholm-Tegner scores) and radiographically by a reviewer independent of the team of operators.

RESULTS

All patients were re-examined at a mean follow-up of 9 years (range, 6-15 years), with 84% satisfied or very satisfied with the procedure. The average IKDC was 74.5 ± 18.5 points. The average Lysholm score was 87.3 ± 11.6 points. The average Tegner score ranged from 6.35 ± 1.53 points prior to surgery to 5.60 ± 1.64 points after surgery (P = 0.001). The average loss was 0.64 points for patients whose presurgery Tegner score was greater than or equal to 7 (P = 0.019) and 0.3 points if lower than 7. The radiologic evaluation of 21 patients showed complete osteointegration of the grafts in 90% of cases.

CONCLUSION

The results of the femoral condyle mosaic autografts are satisfactory, a mean of 9 years after surgery. The most active patients lowered their activity level while the more sedentary did not have to adapt their lifestyle.

Patellar chondral defects: a review of a challenging entity

PURPOSE

The aim of this study was to perform a review of the management of patellar cartilage defects, identify prognostic factors for better clinical outcomes, and propose a treatment algorithm of this challenging entity.

METHODS

We conducted a review of multiple databases, evaluating the clinical outcomes after patellar cartilage lesion treatment. Because of the heterogeneity of data, a meta-analysis could not be performed.

RESULTS

Twelve studies were identified for inclusion. Based on the clinical outcomes of these studies, a treatment algorithm was proposed. The clinical outcomes after patellar cartilage defects repair depend on the location and size of the articular defect, the age of the patient, the successful reconstruction of the patellar ridge, the repair of extensor mechanism malalignment, and the coexistence of chondromalacia.

CONCLUSION

The optimal treatment for cartilaginous defects of the patella is still elusive. More prospective studies are needed, in order to identify which techniques are cost-effective especially on a long-term basis.

Periosteal autograft for articular cartilage defects in dogs: MR imaging and ultrasonography of the repair process

BACKGROUND

Autologous periosteal grafting is used as treatment for cartilage defects.

PURPOSE

To assess the role of MR imaging and ultrasonography in the evaluation of the post-graft repair process with imaging and histologic correlation.

MATERIAL AND METHODS

Periosteal grafts obtained from the tibia of eight dogs were transplanted to the experimental cartilage defects in the femoral condyles (15 knees). The control group was comprised of three dogs (five knees). MR imaging using 4.7T and ultrasonography of the grafted specimens was performed at one, two, four, eight, and 16 weeks after transplantation. The animals were sacrificed at the time of imaging at the previously specified intervals. Histologic analysis with imaging correlation was subsequently performed.

RESULTS

All specimens taken from one to 16 weeks demonstrated periosteal proliferation in the graft. At one week, experimental cartilage defects were no longer present on MR imaging. Area of high signal intensity (SI) in the defect was present which corresponded to hemorrhage, edema, and fibrosis on histology. At two, four, and eight weeks, all but two graft demonstrated heterogeneous high SI on T2-weighted image, consistent with immature cartilage. At 16 weeks, all grafts showed heterogeneous isointense to adjacent cartilage on all sequences, which corresponded to dominant mature cartilage. The repair tissue near the exposed subchondral bone revealed heterogeneous high SI on T2-weighted images. This corresponded to the fibrosis with vascular penetration and edema. In the control group, no cartilage repair was noted within cartilage defects. The serial MR features of the grafted area correlated well with the histologic findings. Serial sonographic findings were not sufficient to provide the regenerated cartilage maturity.

CONCLUSION

MR imaging is capable of depicting the repair characteristics following periosteal grafting for articular cartilage defects. MR imaging may provide useful information in the assessment of the graft appearance with definite implications regarding the degree and success of incorporation.

Autologous chondrocyte implantation for treatment of focal cartilage defects in patients age 40 years and older: A matched-pair analysis with 2-year follow-up

BACKGROUND

Autologous chondrocyte implantation (ACI) is an accepted surgical treatment in patients with isolated cartilage defects of the knee. Age has been considered as a limiting factor and the technique has not been recommended in patients older than 40 to 50 years. Nevertheless, some more recent studies report satisfying clinical results in middle-aged patients.

HYPOTHESIS

Analogous to the microfracture technique, age over 40 years is associated with inferior clinical outcome after ACI.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Thirty-seven patients with an average age of 47.8 years (group 1) were matched with 37 patients with an average age of 31 years (group 2). Both groups underwent ACI for treatment of isolated cartilage defects of the knee. All patients were enrolled prospectively and followed for a period of 24 months using International Knee Documentation Committee (IKDC), Lysholm scale, Cincinnati sports scale, and Tegner activity evaluation instruments.

RESULTS

Statistical analysis revealed a significant increase in function after ACI in both groups as early as 6 months after surgery until the end of the study period. There was only a slight tendency for better clinical outcome in younger patients (IKDC at 24 months: group 1, 72.2 ± 15.8 [standard deviation]; group 2: 76.1 ± 14.1; P = .261; Lysholm at 24 months: group 1: 80.42 ± 15.37; group 2: 80.65 ± 12.01), no statistical significant differences were found between patients of group 1 and group 2 at any of the time points investigated.

CONCLUSION

In contrast to other cartilage repair techniques, patients 40 years and older do not have an inferior outcome up to 24 months after ACI for isolated cartilage defects when compared with younger patients.

Marrow stimulation techniques

Due to the very low intrinsic activity of human adult cartilage, healing of chondral and osteochondral defects in patients cannot be expected. In treating symptomatic cartilage damage, marrow stimulation methods belong to the most frequently used methods, along with autologous chondrocyte transplantation (ACT) and mosaicplasty. These arthroscopic procedures are generally easy and the marrow stimulation treatment costs relatively little. In recent years, Pridie drilling has been increasingly replaced by the microfracture technique. This modification relies on the same biological principles of promoting resurfacing with the formation of fibro-cartilaginous repair tissue. For the treatment of smaller cartilage defects (<2.5 cm(2)), microfracture still remains the first choice for treatment. The clinical results after microfracture in the knee are age dependent. Younger and active patients (<40 years) with smaller isolated traumatic lesions on the femoral condyles have the best long-term results. The deterioration of the clinical results begins after 18 months and is significantly more pronounced in older patients with defects on the patella-femoral joint and tibia. The inferior quality of the repair tissue, partially incomplete defect filling and new bone formation in the defect area seem to be limitations of these methods. The AMIC (autologous matrix induced chondrogenesis) technique was developed to enable treatment of larger defects by the application of a collagen Type III/I membrane (Geistlich Pharma, Wolhusen, Switzerland), in particular when cell-engaged procedures such as ACT cannot be used for financial reasons or because it is not indicated. AMIC seems to be particularly suitable for treating damaged retropatellar cartilage, which is an advantage because these defects can be hard to treat with standard microfracturing alone. The results of the ongoing studies are awaited to establish whether better results with this technology are achievable in the long term.

Strategies for prevention and management of musculoskeletal conditions. Lower limb pain

This article summarises lower limb pathology, which results in lower limb pain. It mainly addresses injuries and deliberately omits osteoarthritis and rheumatoid arthritis, since these entities are described in detail in other chapters in this volume. As major trauma is not a focal point for rheumatologists and repetitive strain injuries of the lower limb are rare, sports and leisure injuries are the main focus. Regarding lower limb pain, this chapter describes the most important problems and quantifies the size of the problem. Furthermore, it informs the reader about different treatment modalities, their goals and methods of measuring the effectiveness of the treatment. Evidence is given for different interventions, such as lifestyle, pharmacological, surgery and rehabilitation. In addition, opportunities to apply these interventions for prevention and treatment to those who will potentially benefit most are shown. Finally, strategies (care pathways) are given for prevention and treatment based on this evidence.

Evaluation of Cartilage Reconstruction by Means of Autologous Chondrocyte Versus Periosteal Graft Transplantation: An Animal Study

BACKGROUND

Autologous chondrocyte transplantation (ACT) has been shown to heal cartilage defects under experimental and clinical conditions. However, the evaluation of successful transplantation still remains arbitrary and further research is required to establish objective criteria of treatment. The aim of the present study was to evaluate the criteria of successful ACT and to compare the results with those obtained following periosteal grafting (PG).

MATERIALS AND METHODS

Articular cartilage specimens were taken from the distal femur of 30 adolescent New Zealand rabbits and chondrocytes were obtained by collagenase digestion. The chondrocytes were identified by a functional assay, based on estimating procollagen type II mRNA by reverse-transcribed polymerase chain reaction. The cells cultured in vitro were transplanted under a periosteal flap into a full thickness defect (ICRS III(0)). The quality of the repaired tissue was evaluated macroscopically according to a modified scale of Brittberg et al, and microscopically according to O'Driscoll et al. For comparative purposes animals treated with PG were used.

RESULTS

Cultured chondrocytes expressed procollagen type II and, upon transplantation into the defect, produced hyaline cartilage. To evaluate the results of transplantation, two categories of criteria were adopted-macroscopic analysis and microscopic examination. By all adopted criteria the results were significantly better in the ACT group (P < .05) than in the PG group.

CONCLUSION

Prior to transplantation, assays for specialized functions of chondrocytes required semiquantitative evaluation of macroscopic and microscopic appearance of the repaired tissue, showing the benefit of autologous chondrocyte versus periosteal graft transplantation.

Rehabilitation After Cell Transplantation for Cartilage Defects

Rehabilitation is a key element of successful treatment of cartilage defects with cell transplantation. The process of graft maturation takes approximately 18 months and cannot be accelerated, but requires carefully introduced steps leading to early recovery of joint function. Rehabilitation starts at 8 hours after surgery with the continuous passive motion (CPM) exercises and physiotherapy. For the first 6 weeks, patients continue with CPM in the range of 0 degrees to 45 degrees for femoral and tibial defects and 0 degrees to 30 degrees for patellofemoral joint reconstruction. Isometric muscle training and scar manual therapy are introduced. Patients are allowed to weight-bear as tolerated from the second week after surgery. After this initial phase, from 6 to 8 weeks after surgery, rehabilitation is accelerated with increased load-bearing and progressive range of motion to full flexion. Usually patients are able to walk without crutches in this time. Proprioceptive training is introduced with the advance of pain-free full range of motion and no discomfort with full weight-bearing. At 6 months after surgery, most patients recover joint function, making it possible for them to return to daily living activities. However, they need to continue with muscle, proprioceptive, and sports-specific rehabilitation exercises. The rehabilitation process is complicated, requiring close cooperation between the patient and surgeon-physiotherapist team to understand the symptoms and address them in a timely fashion.

MR Imaging of Articular Cartilage: Current State and Recent Developments

Osteoarthritis is the most common type of arthritis and a frequent cause of pain and disability. A number of exciting surgical treatment modalities have been introduced recently, including autologous chondrocyte transplantation and osteochondral allografting or autografting. MR imaging offers the distinct advantage of visualizing the articular cartilage directly. MR imaging can detect signal and morphologic changes in the cartilage and has been used to detect cartilage surface fraying, fissuring, and varying degrees of cartilage thinning.

Magnetic resonance imaging of the hip: detection of labral and chondral abnormalities using noncontrast imaging

PURPOSE

Traditional imaging techniques have limited ability to detect subtle chondral and labral injuries of the hip. We performed a retrospective review of patients who underwent magnetic resonance imaging (MRI) of the hip and subsequent hip arthroscopy in order to evaluate the ability of optimized, noncontrast MRI to identify tears of the acetabular labrum and defects in articular cartilage.

TYPE OF STUDY

Retrospective review of a consecutive sample.

METHODS

Between January 1997 and July 2000, 92 patients had MRI of the hip, followed by arthroscopic surgery of that hip by 1 of 2 surgeons (R.B., D.E.P.). Two musculoskeletal MR radiologists blinded to the initial MRI and surgical findings, independently interpreted the studies, looking for the location and degree of articular cartilage and acetabular labral pathology.

RESULTS

Of the 92 patients studied, each of 2 radiologists correctly identified 83 (94%) and 84 (95%) of the 88 labral tears present at surgery, respectively. There was 92% interobserver agreement on the MRI studies. For articular cartilage defects on the femoral head and acetabulum, there was good agreement (92% and 86% within 1 grade) between MRI and surgical grading and between the 2 MR readers (kappa of 0.8 for femoral head cartilage and 0.7 for acetabular cartilage).

CONCLUSIONS

This study shows that noncontrast MRI of the hip, using an optimized protocol, can noninvasively identify labral and chondral pathology. Such information may facilitate deciding which patients warrant surgical intervention, thus preserving hip arthroscopy as a therapeutic tool.

LEVEL OF EVIDENCE

Level II, Development of Diagnostic Criteria Study.

Manual punch versus power harvesting of osteochondral grafts

PURPOSE

The purpose of the study was to analyze the effect on chondrocyte viability of 2 existing methods of harvesting osteochondral grafts used for articular cartilage resurfacing.

TYPE OF STUDY

Acute animal experiment.

METHODS

Power (P) trephine versus manual (M) punch harvesting was tested; 2.7-mm and 4.5-mm dowels were harvested from 8 femoral trochlea from 4 sheep using the Acufex MosaicPlasty system (Andover, MA). Grafts were harvested perpendicular to the articular surface to a depth of 10 mm under constant saline irrigation. Power trephine grafts (n = 46, 2.7 P; n = 45, 4.5 P) were harvested by coupling the serrated trephine to a standard orthopaedic nitrogen powered drill. Manual punch grafts (n = 41, 2.7 M; n=33, 4.5 M) were harvested by malleting the punch to the required depth, minimizing rocking, and only slightly turning the punch on removal. Five 40-microm-thick fresh cartilage sections oriented perpendicular to the articular surface were obtained from each graft and then stained with Syto 13 and ethidium bromide vital stains, and the proportion of live cells per field and physical damage were compared between groups. Masson's trichrome stain was used on paraffin-embedded histologic sections.

RESULTS

Power harvesting was technically more difficult and resulted in more gross and light microscopic damage to the osteochondral grafts. Chondrocyte viability was significantly greater for manual punch versus power harvesting of both graft sizes (P <.005). Chondrocyte viability was greater for 4.5 P versus 2.7 P grafts (P <.005), but no difference was found between the 2.7 M and 4.5 M groups (P =.357).

CONCLUSIONS

Chondrocyte viability is significantly greater using manual punch versus serrated power trephines when harvesting osteochondral grafts for cartilage resurfacing procedures. Power trephines should not be used for this procedure.

CLINICAL RELEVANCE

This study shows that the original method (power trephine) of harvesting osteochondral grafts results in great loss of chondrocyte viability versus manual punch harvesting and should no longer be used.

Magnetic resonance imaging of focal articular cartilage lesions

Lesions of the articular cartilage now are recognized as a common, often treatable source of joint disability. Magnetic resonance imaging (MRI) of articular cartilage is a sensitive, noninvasive method for the detection of focal articular cartilage lesions. Advancement in imaging technology now allows for high spatial resolution acquisitions that are able to identify most cartilage lesions, and these acquisitions can be incorporated into everyday clinical imaging protocols. Thus, screening for cartilage abnormalities can be accomplished, along with routine evaluation for ligament and meniscal abnormalities. Familiarity with the appearances of normal cartilage and the full spectrum of cartilage lesions will aid in specific diagnoses. Grading and sizing of cartilage lesions and any underlying bony abnormalities on MRI can help the surgeon in treatment planning; however, some significant cartilage lesions can be difficult to identify and grade by MRI.

Arthroscopic mosaic arthroplasty in the equine third carpal bone

OBJECTIVE

To investigate survival and function of autogenous heterotopic osteochondral grafts in a site where injuries are common.

STUDY DESIGN

Three osteochondral grafts were harvested arthroscopically from the femoropatellar joint and transplanted to the third carpal bone (C(3)). Nine months later, histologic, histomorphometric, and biochemical comparisons were made between the transplanted grafts in C(3) and tissue adjacent to the recipient site, the opposing radial carpal bone (C(r)), the donor site in the femoropatellar joint, and the sham-operated contralateral C(3).

ANIMALS

One mixed-breed pony and 5 Standardbred horses aged 3 to 8 years old.

METHODS

Using instruments modified for equine use, four 4.5-mm-diameter osteochondral grafts were harvested arthroscopically from the distal aspect of the lateral trochlea of the right femur and inserted into the radial facet of the right third carpal bone. The fourth graft was kept as a donor-site control sample. Three months later, regular exercise was started and at 6 months, repeat arthroscopy was conducted to evaluate healing. The horses were euthanatized 9 months after transplantation, and comparisons were made between the grafts, opposing radial carpal bone, and contralateral third carpal bone. The assessment criteria included paravital staining, a modified Mankin scoring system, and biochemical analyses for collagen type, total collagen content, and sulfated glycosaminoglycan concentration.

RESULTS

All horses were sound 21 days' postoperatively. At 6 months, all 18 grafts were intact but somewhat soft and opaque compared with surrounding carpal cartilage. Nine months' postoperatively, the bony portions of the grafts were well integrated with the recipient sites, but 6 grafts had histologic evidence of cartilage degeneration. From biochemical analysis of grafts, there was little or no new repair tissue invading the experimental sites, but sulfated glycosaminoglycan (proteoglycan) loss from the transplanted cartilage was marked.

CONCLUSIONS

Heterotopic transfer of osteochondral grafts from the distal aspect of the lateral femoral trochlea to the third carpal bone is feasible with minor modifications of human mosaic arthroplasty instruments. The bony portion of the osteochondral grafts was quickly remodeled to provide subchondral support to the transplanted articular cartilage. The loss of proteoglycan from the transplanted cartilage indicates that the grafts might have been injured during harvesting or insertion, or, more likely, did not remodel to meet the demands of a new biomechanical environment.

CLINICAL RELEVANCE

These findings suggest that arthroscopic resurfacing of focal osteoarticular defects will not be successful in the long term unless donor and recipient sites can be matched with respect to cartilage thickness, biochemical constituents, and physical properties. Mosaic arthroplasty may be indicated in selected cases in which no other options exist to create a confluent cartilage-covered surface.