- Bony Impingement:
- pts who have persistent pain in anterior aspect of ankle & who have
anterior tibiotalar spur
evident on a lateral roentgenogram need additional diagnostic evaluation
and management;
- extreme dorsiflexion required by the demiplie position in ballet can
lead to impingement of anterior lip of tibia on talar neck;
- natural sulcus is present on superior aspect of talar neck & accomodates
anterior tibial
ridge in most ordinary circumstances of dorsiflexion;
- however, w/ hyperdorsiflexion in ballet dancing can produce direct
contact between the tibia and the talus;
- w/ repeated impingement, exostoses form, providing basis for anterior
impingement syndrome;
- Soft Tissue Impingement:
- may arise from
ankle sprains, but physical exam may fail to show instability;
- may occur along the anterolateral portion of the ankle just above the
ATFL;
- radiographs may be unremarkable;
-
diff dx:
-
equinus
contracture:
- Exam:
- tenderness is present between anterior tibial tendon &
medial
malleolus;
- tenderness accentuated with dorsiflexion and relieved w/ plantar flex;
- w/ ankle in plantar flexion, exostoses can be palpated on superior surface
of the talar neck;
- tenderness is present on the anterolateral aspect of the ankle joint;
- Radiographs:
- lateral x-ray demonstrates hyperdorsiflexion contact of the anterior lip
on talar neck;
- lateral dorsiflexion-stress roentgenogram may also show abutment between
anterior tibial spur and the talus;
- consider radiographs of the opposite foot to determine the angle between
the talus and calcaneus;
- Non Operative Treatment:
- as both a diagnostic and therapeutic measure, single intra-articular
injection of long-acting anesthetic, w/ or w/o
use of cortisone, combined with a felt one-centimeter heel-lift can
sometimes eliminate all painful symptoms;
- Treatment:
- arthroscopic or open resection of spur may be considered (see:
ankle
arthroscopy);
- w/ large spurs consider open arthrotomy over arthroscopic excision;
- w/ arthroscopic technique, do not use distraction of the joint because it
results in tightening of the anterior capsule,
which makes it more difficult to identify the osteophytes;
- spurs are identified when the ankle is in a fully dorsiflexed position
(dorsiflexion also helps avoid iatrogenic
injury to the talus);
- operative radiographs should be compared to preopeartive radiographs;
- Outcomes:
- in the report by C. Niek van Dijk MD, PhD (Am Jour of Sports Medicine Vol
25. No 6 Nov-Dec 1997)
- 62 consecutive patients with painful limited dorsiflexion of the
ankle not responding to nonoperative
treatment
participated in a prospective study;
- all underwent arthroscopic surgery;
- preoperative radiographs were graded according to an osteoarthritic
and an impingement classification;
- results showed that the degree of osteoarthritic changes is a better
prognostic factor for the outcome
of arthroscopic
surgery for anterior ankle impingement than size and location of the spurs;
- hypothesis is that osteophytes without joint space narrowing are not
a manifestation of osteoarthritic
changes but
rather the result of local (micro)trauma;
- after 2 years, 73% of the patients experienced overall excellent or
good results; 90% of those
without joint space narrowing had good or excellent results;
- 50% of those with joint space narrowing had good or excellent
results.
- at the 2-year followup, the group without joint space narrowing
showed significantly better
scores in pain, swelling, ability to work, and engagement in
sports;
- history of anterior ankle pain of less than 2 years and an
anteromedial impingement
(as opposed to an
anterolateral) resulted in superior patient satisfaction;
- in the report by JL Tol et al, the authors performed a prospective study
to assess the long-term outcome
of 57 arthroscopic debridement procedures carried out to treat anterior
impingement in the ankle;
- using preoperative radiographs, we grouped patients according to the
extent of their osteoarthritis (OA);
- symptoms of those with grade-0 changes could be attributed to
anterior soft-tissue impingement alone;
- patients with grade-I disease had both anterior soft-tissue and
osteophytic impingement, but no narrowing
of the joint
space;
- in those with grade-II OA, narrowing of the joint space was
accompanied by osteophytic impingement;
- radiographs taken before and after operation and at follow-up were
compared to assess the recurrence
of osteophytes
and the progression of narrowing of the joint space;
- at a mean follow-up of 6.5 years (5 to 8) all patients without OA
had excellent or good results;
- there were excellent or good results in 77% of patients with grade-I
OA, despite partial or complete
recurrence of osteophytes in two-thirds;
- in most patients with grade-II OA, narrowing of the joint space had
not progressed at follow-up;
- there was a notable improvement in pain in these patients,
53% of whom had excellent or good results;
- although some osteophytes recurred, at long-term follow-up
arthroscopic excision of soft-tissue overgrowths
and osteophytes proved to be an effective way of treating
anterior impingement of the ankle in patients
who had no narrowing of the joint space;
- ref: Arthroscopic treatment of anterior impingement in the ankle. A
PROSPECTIVE STUDY WITH A FIVE- TO EIGHT-YEAR FOLLOW-UP.
J. L Tol, C. P. P. M. Verheyen, C. N. van Dijk. J Bone Joint
Surg [Br] 2001;83-B:9-13.