Articular cartilage injuries ( Fig. 1 ) are common findings during arthroscopy 1 and diagnostic imaging of the joints 2,3. While there are many techniques for the treatment of cartilage injuries, not enough is known about which lesions need treatment or about the proper treatment modality for a particular lesion. More objective data regarding cartilage injuries and more accurate methods to evaluate the operative outcomes are required, especially since new procedures are becoming increasingly expensive. There are many published reports on the outcomes of total joint replacement based on clinical scores and radiographic evaluations. However, it has been quite difficult to interpret the reported results of the repair of focal cartilage defects as there is no universally accepted system to describe the lesions, the repair tissue, or the clinical symptoms for this category of patients. More studies on clinical articular cartilage resurfacing will appear in the future, making it important to develop common evaluation measurement tools and standards. The International Cartilage Repair Society (ICRS) was founded in 1997 and has been interested in developing a standardization system for the evaluation of cartilage injury and repair 4,5. A working group of the ICRS was established with the aim of developing a common, easy system for clinical and arthroscopic evaluation ( Table I ). Shortly thereafter, the Articular Cartilage Imaging Committee of the ICRS was created to assess the existing clinical imaging techniques, to recommend specific magnetic resonance imaging techniques for the assessment of articular cartilage 6, and to develop a standardized magnetic resonance imaging evaluation system for native and repaired cartilage ( Table I ). A state-of-the-art system for clinical cartilage evaluation and imaging assessment is presented below.



Fig. 1: 
A cartilage lesion on a femoral condyle, extending deep down to bone. Note that some calcified …

Evaluation of Cartilage Injuries and Repair

We evaluated the durability of autologous chondrocyte transplantation grafts in 61 patients treated for isolated cartilage defects on the femoral condyle or the patella and followed up for a mean of 7.4 years (range, 5 to 11). Durability was determined by comparing the clinical status at the long-term follow-up with that found 2 years after the transplantation. After 2 years, 50 of the 61 patients had good or excellent clinical results, and 51 of 61 had good or excellent results at 5 to 11 years later. Grafted areas from 11 of the patients were evaluated with an electromechanical indentation probe during a second-look arthroscopy procedure (mean follow-up, 54.3 months; range, 33 to 84); stiffness measurements were 90% or more of those of normal cartilage in eight patients. Eight of twelve 2-mm biopsy samples taken from these patients showed hyaline characteristics with safranin O staining and a homogeneous appearance in polarized light. Three fibrous and eight hyaline biopsy specimens stained positive to aggrecan and to cartilage oligomeric matrix protein. Hyaline-like specimens stained positive for type II collagen, and fibrous, for type I collagen. Autologous chondrocyte transplantation for the treatment of articular cartilage injuries has a durable outcome for as long as 11 years.

Autologous Chondrocyte Transplantation Biomechanics and Long-Term Durability

Purpose: Focal chondral or osteochondral defects can be painful and disabling, have a poor capacity for repair, and may predispose patients for osteoarthritis. New surgical procedures that aim to reestablish hyaline cartilage have been introduced and the results seem promising. The purpose of this study is to provide reliable data on chondral and osteochondral defects in patients with symptomatic knees requiring arthroscopy and to calculate the prevalence of patients who might benefit from cartilage repair surgery. Type of Study: Prospective study. Methods: One thousand consecutive knee arthroscopies were included in this study. Immediately after each arthroscopy, the surgeon completed a questionnaire providing detailed information about the findings. Chondral and osteochondral lesions were classified in accordance with the system recommended by the International Cartilage Repair Society (ICRS). Results: Chondral or osteochondral lesions (of any type) were found in 61% of the patients. Focal chondral or osteochondral defects were found in 19% of the patients. In these patients, 61% related their current knee problem to a previous trauma, and a concomitant meniscal or anterior cruciate ligament injury was found in 42% (n = 81) and 26% (n = 50), respectively. The mean chondral or osteochondral total defect area was 2.1 cm 2 (range, 0.5 to 12; standard deviation [SD], 1.5). The main focal chondral or osteochondral defect was found on the medial femoral condyle in 58%, patella in 11%, lateral tibia in 11%, lateral femoral condyle in 9%, trochlea in 6%, and medial tibia in 5%. It has been suggested that cartilage repair surgery may be most suitable in patients younger than 40 to 50 years old. A single, well-defined ICRS grade III or IV defect with an area of at least 1 cm 2 in a patient younger than 40, 45, or 50 years accounted for 5.3%, 6.1%, and 7.1% of all arthroscopies, respectively. Conclusions: Our study supports the contention that articular cartilage defects are common. It has the advantages of a prospective design and use of a new classification system recommended by the ICRS. This modern system focuses on objectively measurable parameters of the lesion's extent and not its surface appearance. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 7 (September), 2002: pp 730–734

Articular cartilage defects in 1,000 knee arthroscopies

Twenty-five patients with 30 chondral lesions of the knee were treated with an autogenous strip of costal perichondrium. The graft was fixed to the subchondral bone with Tissucol (Immuno, Vienna), a human fibrin glue. The leg was then immobilised for two weeks followed by two weeks of continuous passive motion. Weight-bearing was permitted after three months. The mean knee score (Ranawat, Insall and Shine 1976) changed from 73 before operation to 90 one year after; in 14 patients evaluated after two years there was no decrease. In 28 cases the defect was completely filled with tissue resembling articular cartilage. We conclude that in most cases perichondral arthroplasty of cartilage defects of the knee gives excellent results.

Perichondral grafting for cartilage lesions of the knee.

Autologous chondrocyte implantation has been used since March 1995 in a prospective cohort evaluation. One hundred sixty-nine patients, 13 to 58 years, have been treated as of December 1999. One hundred seven patients have greater than 12 months followup, and 56 have greater than 24 months followup. Overall 87% of patients improved. Patient assessment instruments include the modified Cincinnati knee rating scale, Short Form-36, Knee Society score, Western Ontario McMaster Universities Osteoarthritis Index score, and patient satisfaction survey. Treatment cases included the following categories: Simple (N = 12) isolated femoral condyles; Complex (N = 86) nonarthritic knees with multiple defects on the femur, or isolated lesions to the patella or tibia; and Salvage (N = 71) knees with early arthritic changes. The areas treated were large: Simple, 4.3 cm2 (one defect); Complex, 6.75 cm2 (4.5 cm2 per defect x 1.5 defects per case), and Salvage, 11.66 cm2 (5.3 cm2 per defect x 2.2 defects per case). Patients who had complex and salvage treatments (N = 107) with greater than 1 year followup frequently had adjuvant treatments including valgus tibial (N = 24) or tibial tubercle (N = 15) osteotomies or ligament reconstruction (N = 5). At the 2-year followup, statistically significant functional improvements occurred in the patients in the Simple and Complex categories (Cincinnati score; Simple, baseline 3.57, 24 months = 5.38; Complex, baseline 3.40, 24 months = 6.06). Patients in the Salvage category had statistically significant improvement in Short Form-36 quality of life scores (Physical summary, 24 months) and an increase in the Cincinnati rating scale when the patellofemoral joint was not involved. Patient satisfaction at 24 months for Simple, Complex, and Salvage categories was 60%, 70%, and 90%, respectively. There were 22 failures in 169 patients treated (13%), which was defined as no clinical improvement or graft failure.

Autologous chondrocyte implantation for focal chondral defects of the knee.

Sixty-five articular cartilage knee lesions were diagnosed by arthroscopy over a 5-year period, and classified according to the age, the size, the depth, and the location of the lesion. The purpose of this study was to evaluate surgical outcome of a standardized treatment regimen consisting of complete vertical excision of diseased or injured articular cartilage followed by drilling of the subchondral bone plate. A standardized postoperative rehabilitation protocol was used, which included non-weight bearing for eight weeks. Overall clinical results at two years revealed 69% good, 3% fair, and 28% poor knees. Seventy-one percent of patients underwent follow-up arthroscopy at 1 year and 57% consented to biopsy. Retrospective analysis revealed that the group with the best prognosis consisted of small-to-medium acute partial thickness lesions on the weight bearing portion of the femoral condyles. Ninety-five percent of this group had good results.

The classification and treatment of acute articular cartilage lesions

Lateral release is a reliable component of any surgical treatment of patellofemoral dysfunction or “chondromalacia patella,” good to excellent results in approximately 80% of cases having been reported by numerous investigators. This study confirms the efficacy of the procedure and highlights the features of the open technique as compared with the arthroscopic method. We advocate diagnostic arthroscopy for complete evaluation of the joint. Particular attention is drawn to the anatomic structures that must be divided and the care taken to secure hemostasis to optimize results. Since no correlation was found between the severity of chondromalacia and the final results, this study casts doubt on the value of shaving the rough articular surface.

Robert B. Dzioba

Papers

The classification and treatment of acute articular cartilage lesions

Diagnostic arthroscopy and longitudinal open lateral release: A safe and effective treatment for “chondromalacia patella”