Tibial tubercle advancement osteotomy with bone allograft for patellofemoral arthritis: a retrospective cohort study of 50 knees.
[trochlear dysplasia]
Forty consecutive patients (21 females and 19 males) in a single centre underwent 50 tibial tubercle advancement osteotomy procedures for patellofemoral arthritis between January 1993 and April 2007. Twenty knees with patellar maltracking also underwent medialisation of the tibial tubercle (6-12 mm) in addition to the standard 10-15 mm elevation. Femoral head bone allograft blocks were utilised in all cases, and all patients achieved bony union without further surgery. Forty-five knees had previously undergone arthroscopy, 18 with arthroscopic lateral releases.Ninety-four percentage of knees had sustained improvement in visual analogue pain scores (mean improvement of 37.4, P < 0.05) at a mean follow-up of 81 months (range 26-195 months), with 96% of patients still satisfied; and 92% of knees had sustained improvement in Shelbourne and Trumper anterior knee function scores (mean improvement of 39.8, P < 0.05). Overall clinical outcomes were rated excellent/good in 77%, fair in 35% and poor in 8% of knees. Two knees required arthroplasty surgery over the follow-up period (at 18 months and 8 years), and their anterior knee pain and function scores were not included in the analyses. Six knees (12%) suffered major complications: 1 temporary common peroneal neuropraxia; 2 intraoperative tibial metaphyseal fractures; and 3 tibial tuberosity fractures (at 8 days, 3 weeks and 3 months). Four knees (8%) suffered superficial wound infections, 31 knees had some numbness around the midline scar, 7 knees had scar pain lasting up to 12 months, and 22 knees (44%) experienced some discomfort relating to the metalwork, which was removed in all these cases.Tibial tubercle advancement osteotomy can be an effective treatment for anterior knee pain and for patients with arthroscopic evidence of patellar chondral damage. It can provide excellent/good long-term functional results in the majority of patients, with very high satisfaction levels and sustained improvement in pain symptoms. The use of femoral head bone allograft is both effective in obtaining bony union and by definition avoids the donor-site morbidity. Knees with patellar malalignment may also undergo individualised medialisation of the tibial tubercle such that the patella lies in the centre of the femoral trochlea, and may benefit from lateral trochleaplasty surgery in the presence of trochlear dysplasia. However, the major operative complication rate is high at 12%, and fracture of the tibial tubercle is associated with a poorer outcome. One can expect 10% of operated knees to have had some clinical deterioration in the patellofemoral joint by a mean follow-up of 93 months.
