Introduction

In 1989, as a young orthopaedic intern, I witnessed my first cartilage repair procedure: an osteochondral allograft in a 28-year-old man with osteonecrosis of the femoral head. I was fascinated by the elegance of replacing diseased tissue with healthy tissue- like for like- versus the metal and plastic joint replacements I was routinely exposed to as a trainee. I was also lucky in a way. Training in San Diego, where fresh allograft transplantation surgery was being pioneered, afforded the opportunity to learn from pioneers and become interested from the beginning of our joint preservation specialty. Eight years later, when I returned to San Diego as a young faculty member, I remember the day that Lars Peterson and Matts Brittberg ACI study was published in the New England Journal of Medicine, which effectively launched the era of cartilage repair as we know it today. It has been a pleasure and a privilege to participate in this field.

Content

What are my best experiences? Certainly, it is the friendships and collegiality I have experienced worldwide. It is not many who can say they are privileged to have friends around the world! It is also the trust and gratitude of patients that I have helped when they were told nothing more can be done (and now seeing them thrive 20 years later).

What are my worst experiences? Doing an operation that does not help the patient and seeing their hope fade. And, after 30 years in joint preservation and arthritis care, knowing I (and we) have made little progress in solving the ultimate puzzle of the arthritic joint. I have learned a lot of ways to tell patients they have an incurable disease! Let’s agree that cartilage repair and joint restoration is hard work. I have a special day of the week to take care of these patients- usually Fridays so there can be a “happy hour” after clinic. Most of my allograft surgeries take place at night, after the regular day of work is done. Bad experience?

Aside from philosophy, there is a practicality to experience that informs us about how we did and how we can be better. We often know this intuitively, but science demands data. We have collected, prospectively, data on every single joint preservation procedure we have performed in the last three decades. The size and quality of this database has become a powerful tool in our understanding “best and worst”. I don't remember the source but I am fond of the saying “those that have data need not shout”

At this meeting we will report predictors of failure of fresh osteochondral allografts along with outcomes in “ideal patients”, literally the two ends of the spectrum. We all know that young patients (under 30 years) with healthy joints and focal traumatic cartilage lesions or OCD have predictably good outcomes and thus fall into my “best experience” category. Ironically, I have also learned that isolated trochlea lesions have great outcomes (think of how rare this is, most bad patellofemoral joints start with patella lesions). I can confidently tell them (and their parents) we have over 90% chance of success and I know from my data these knees are functioning normally. Ironically the very worst patella cartilage disease often is a good allograft experience. Patients seem to be genuinely happy with a knee you or I might not like but one that is infinitely better than the disaster they lived with. Less obvious is the other best case for me: usually lateral, but sometimes medial, degenerative lesions with malalignment and some amount of meniscal deficiency. I have learned to love the distal femoral osteotomy, like the high tibial osteotomy and am ambivalent about meniscal transplantation. It’s what the data and my patients tell me

What does the data tell me is the worst? Trying to be heroic and treat multicompartment knee arthritis. After 20 years I haven’t figured that out and I don't think anyone else has. I just don't do it, particularly in middle aged people. My data says that if you are over 40, have OA or degenerative chondral lesions and have grafts in more than one compartment, your chance of “success” long term is no more than 40%. The same holds true for the patellofemoral joint with bipolar disease and the typical dysplasia/ malalignment. To me this often goes beyond a disease of the organ (the synovial joint) and becomes a disease of the organism. How can cartilage repair restore a whole limb that is dysfunctional? As an arthroplasty surgeon I am much more confident in success with metal and plastic implants in this group. I’ll still try joint preservation in young people under 30 but it has to be a special case.

One thing that I have observed in the world of joint preservation, is that most of us have come to similar conclusions in our own “experience. I find that remarkable, but it is probably predictable as well. Experience is teaching us every day. Outcome data is getting incrementally better with every passing year. One day I hope we all can talk about how we solved the “worst experience” phenomenon in joint preservation

Results

Treatment failure occurred in 78 knees (16%); 58 conversions to arthroplasty, 19 revision allografting, and 1 patellectomy. Age, diagnosis, and graft size independently predicted a higher risk of failure (Table 2). Patients who were ≥30 years old were 2.4 times more likely than younger patients to experience a treatment failure. Compared to patients with osteochondritis dissecans or traumatic chondral injury, patients with degenerative chondral lesions, avascular necrosis, or osteoarthritis were more likely to have allograft failure. Grafts >8 cm² were 2.1 times more likely to fail than grafts ≤8 cm². Anatomic location and number of grafts were associated with failure in univariate analyses, but not after controlling for other variables in the multivariate analysis.

Results

Seventeen knees (18%) underwent reoperations. Two knees (2%) were classified as OCA failures (one revision OCA at 2.7 years and one conversion to unicompartmental arthroplasty at 10.2 years). Survivorship was 99% at 5 and 10 years. Pain and function improved (Table 1.), and 93% of patients were satisfied with the results of the OCA transplantation.