Purpose: One of the difficult problems during the implantation of a total knee prosthesis is the presence of preoperative stiffness or permanent flexion.The later is a sign of advanced stage degradation due to osteoarthritis or rheumatoid arthritis. We wanted to describe the technical specificities of a total knee arthroplasty (TKA) implanted in patients with permanent flexion and to analyse long-term outcome.

Material and methods: We studied a series of 826 posterior stabilised TKA (HLS) implanted since 1988 (followed prospectively since 1995). We defined three groups of patients according to the degree of preoperative flexion: group I (0°–10°), group II (11°–20°), and group III (> 20°). We evaluated the operative technique itself, then analysed long-term clinical and radiological outcome using the IKS scores.

Results: There was no significant difference in the objective or subjective clinical or radiological outcomes in the first two groups (I and II). Outcome appeared to be less satisfactory in patients with permanent flexion greater than 20°, but the statistical analysis was not feasible.

Discussion: This study enabled us to describe the specific preoperative planning and the operative steps necessary for patients with permanent flexion preoperatively. The results of our series do no enable distinction between the long-term results in patients with < 20° flexion. Beyond this level, techniques for bony or ligamentary release influence the results which are less satisfactory. Posterior stabilisation enables release of the posterior cruciate ligament in order to improve joint recovery.

Conclusion: Preoperative planning for TKA must of course take into account bony deformation, but also preoperative joint motion. In the event of permanent flexion, the operative technique must be adapted. This allows correct position of the implant and improved joint motion.

Purpose: We report the results of a prospective consecutive series of 25 patient with non-degenerative chondral lesions treated by mosaicplasty osteochondral grafts.

Material and method: The main group was composed of 22 knees, including 16 with osteochonritis dissecans, five with cartilage damage concomitant with chronic anterior laxity, and one with necrosis of the medial condyle. The other lesions involved the talus. Mean patient age was 28 years. Mean follow-up was 13 months (range 1 – 39 months). Among the knee group, 15 patients underwent standard mosaicplasty. The lesion measured 1.96 cm2 on the average. For the other cases, associated procedures included: valgus tibial osteotomy (n=4), anterior ligamentoplasty (n=3). There were few complications except one case of infection. Clinical assessment was based on the new ICRS chart (with an updated IKDC subjective score sheet). The subjective IKDC score was 48.7% preoperatively.

Results: Mean coverage of the lesion was 68.5%. Solitary mosaicplasty provided good results. The subjective IKDC score was 67.5% and 77% of the patients experienced little or no pain in their knee. Two-thirds of the patients scored their performance at 8 or more on the 10 point scale. The objective IKDC score gave 11/15 A and 4/15 B. There was one complication related to the donor site causing femoropatellar impingement after harvesting substantial graft material. Recovery was more difficult for patients with associated procedures and results were less satisfactory. All patients underwent an MRI at six months that showed in general a good morphological aspect.

Discussion: The technique used is particularly important due to a number of pitfalls and difficulties requiring much surgical skill. While we have found that most associated procedures such as grafting the anterior cruciate ligament are warranted, the appropriateness of an associated osteotomy would be highly debatable. Lesions measuring more than 3 cm2 correspond to the limit of this technique.

Conclusion: Mosaicplasty is a reliable method for cartilage repair. Long-term assessment will allow better indications and identification of any iatrogenic factors in order to determine the appropriate place for this technique among the other methods used for cartilage repair.