Oslo Sports Trauma Research Center

Intoduction

... but no functional or radiological differences were detected at 10 years follow-up. This is the message from a research team from the OSTRC and Akershus University Hospital who recently published the results from their randomized controlled trial in the KSSTA-Journal.

In young adults, cartilage lesions following a knee injury are quite common findings during arthroscopic examinations. Deep cartilage lesions often contribute to disability, lack of return to sport, and premature osteoarthritis.

Various cartilage repair techniques have been developed and short-term outcomes, in regard to pain relief and knee-function, are respectable.

There is, however, a lack of knowledge regarding the long-term outcome following most of these cartilage repair techniques.

“Microfracture-technique” is probably the most widely used surgical technique to address cartilage injuries, as the procedure is cheap and not very demanding for the orthopaedic surgeon to perform.

However, following surgery, the cartilage defect fills with fibrocartilage, which is known to exhibit inferior mechanical properties compared to native cartilage.

On the other hand, the “mosaicplasty” technique is a method to transplant autologous osteochondral plugs to the damaged area, and thereby provides a hyaline-cartilage-covered surface.

This technique is, hoever, more demanding to perform, and sometimes leaves a symptomatic donor site.

The aim of this study was to investigate the long-term outcome following “microfracture-“ versus “mosaicplasty-technique”.

25 patients with a 10 year follow-up

25 patients (mean age 32 years) with an isolated deep cartilage lesion were enrolled in the study and randomized to either “microfracture” or “mosaicplasty”.

At a median follow-up of almost 10 years, all patients reported knee function through the Lysholm score and the Knee injury and Osteoarthritis Outcome Score (KOOS). Moreover, quadriceps and hamstring strength measurements were available for 22 patients, and a radiographic examination (Kellgren & Lawrence criteria) for 23 patients.

Significant improvements in function and muscle strength

At follow-up, both treatment-groups reported significant increase in knee function compared to baseline, measured by Lysholm score, KOOS and isokinetic muscle strength assessments.

However, no significant differences were detected between patients treated with “microfracture” versus those treated with “mosaicplasty”.

Osteoarthritis was detected in the affected knee in 5 out of 11 patients in the “microfracture-group” and in 2 out of 12 affected knees in the “mosaicplasty-group”.

Cartilage injuries remain a long-term health concern

Even though the study patients achieved an improvement in knee function at 10 years follow-up compared to baseline, they reported a significantly inferior knee function compared to a normal, healthy population.

This study verifies that deep focal cartilage injuries are a serious concern for the patient and a challenging task for the orthopaedic surgeon. The long-term functional outcome following “microfracture-“ and “mosaicplasty-procedures” are comparable, but still not more than modest.