Arthroscopic Surgery for Patellar Tendonitis: A One to Four Year Follow
D P Johnson
The histological appearances of patellar tendonitis were reported by
Martens in 1982, and assumed to represent a micro fracture or a partial
rupture of the tendon. Surgical techniques are sometimes required in the
management and include detachment of the patella tendon from the inferior
pole, excision of the degenerative nodule, drilling, or excision of the
inferior pole, which are all reported to be successful in 60 - 90% of
cases. In a previous study of the radiological and MRI appearances in
this condition, a normal morphology of the patella, and an increased high
signal intensity in the superior, central and posterior aspect of the
tendon was noted. It was, proposed that a possible pathogenesis for this
condition may in fact be an impingement or compression of the inferior
pole of the patella onto the posterior aspect of the tendon in flexion.
If correct, the surgical rational should be to release the deeper fibres
of the tendon from the inferior pole and to surgically excise the tip.
An inital study of 20 patients treated by arthroscopic decompression and
marginal excision of the inferior pole was first presented 2 years ago.
This study analysed the 1-4 year results in a larger population.
We analysed a population of 35 patients with patella tendonitis resistant
to conservative treatment undergoing release of the deep central aspect
of the tendon and excision of the inferior pole undertaken as a wholy
arthroscopic procedure with a 1-4 year follow up. The patients had significant
grade III patella tendonitis. The technique included elevation and partial
excision of the superior central part of the fat pad to reveal the bare
area of the patella. Elevation of the patella tendon fibres from the anterior
5 millimetre surface of the inferior pole of the patella, and excision
of the exposed inferior pole. Patients were mobilised and discharged as
a day case in over 50 per cent of cases. The average operating time was
45 minutes. There was no instance of instrument breakage. No conversion
to an open procedure or operative complications. There were no re-admissions
for haemarthrosis. Final review revealed that 90% of patients had good
or excellent results. One patient had a fair result, one had a poor result.
Patients returned to work on average in 2 weeks, sport on average in 9
weeks, became symptom free in 10 weeks, and returned to competition on
average in 13 weeks following surgery.
We, therefore, concluded that decompression of the inferior pole of the
patella by elevation of the central portion of the tendon from the inferior
pole and excision of the inferior pole without specific excision of the
degenerative lesion was successful in 90% of cases. It was technically
feasible to undertake this as a day surgery arthroscopic procedure with
rapid rehabilitation. We are currently analysing histological specimens
from 8 cases of patellar tendonitis, but the previously reported appearances
are compatable with a chronic repetative posterior impingement on the
tendon. We have previously suggested a new patho-aetiology of patellar
tendonitis; of a posterior impingement to the tendon and subsequent degeneration.
The results of this study certainly support this aetiology of the condition.
The condition is best investigated by MRI, surgical treament should be
aimed at release of the deep fibres of the tendon from the patella and
excision of the tip of the inferior pole. This can reliably, safely and
successfully be undertaken as an arthroscopic day surgery procedure.