How often do you treat ankles? I know that I treat them every day, and it is likely that you do to. It is not surprising then that Fong et al (2007) found that ankle injuries are the most common injuries in a wide variety of popular sports. However, do you find it surprising that Saxena et al (2007) suggest that osteochondral lesions may be prevalent in up to 50% of ankle injuries? Yeah, me too. Thus, they are likely more common than you may have previously thought.
I feel that the main reason that they are frequently underrecognised is that osteochondral lesions are challenging to diagnose. The symptoms are often vague, and difficult to differentiate from the frequently concomitant ligamentous injury. Therefore, this article aims to present an overview of the evidence based assessment and management of osteochondral lesions of the ankle.
As sports physiotherapists some may incorrectly assume that osteochondral lesions are only associated with acute trauma, as in a sporting injury. However, the presentation can also be associated with local avascular necrosis, systemic vasculopathies, chronic microtrauma, endocrine or metabolic factors, degenerative joint disease, joint malalignment and genetic predisposition (O’Loughlin et al, 2010). Whilst these will not be discussed, I feel it is important to be aware of them.
As suggested above, as sports physiotherapists we will most commonly deal with the cases of acute trauma that are related to sporting injuries. Berndt and Hardy (1959) attempted to reproduce the mechanism of talar dome injuries. They found that lateral injuries were related inversion and dorsiflexion, and that posteromedial injuries with inversion and plantarflexion. The osteochondral surfaces are also in greater risk when the joint is loaded. Thus, osteochondral lesions will frequently present with concomitant ligamentous, general lateral, injuries.
The most widespread classification system for osteochondral lesions was originally developed by Berndt and Harty (1959). The system uses a 4 point grading of the lesions based on the damage to osteochondral surfaces. The grading is as follows:
- I – Subchondral Fracture
- II – Chondral Fracture
- IIa Subchondral Cyst
- III – Chondral Fracture with separated but non-displaced segments
- IV – Chondral Fracture with separated and displaced segments
ASSESSMENT AND DIAGNOSIS OF OSTEOCHONDRAL LESIONS
As previously stated, the assessment and diagnosis of osteochondral lesions is frequently challenging. However, the best available evidence (which unfortunately comes from case series) shows there are a few hallmarks of osteochondral lesions. These include:
- Exertional ankle pain i.e. exacerbated by activity. Rolf et al (2006) found this was present in 95% of cases.
- Reports of chronic ankle instability (Saxena et al, 2007)
- Joint Line Tenderness present in 95% of cases (Rolf et al, 2006)
- Effusion present in 75% of cases (Rolf et al, 2006).
- XRay – will frequently be the first line of imaging. However, x-ray is likely to miss up to 50% of osteochondral lesions (O’Loughlin et al, 2010).
- CT – will allow for a better imaging of the bony surfaces. However, cannot assess the cartilage surfaces.
- MRI – considered the gold standard of imaging for identifying osteochondral lesions. However, studies have shown variable diagnostic accuracy of MRI in diagnosing osteochondral lesions. Sensitivity 73 – 95% and a specificity of 100% (Joshy et al, 2010; Mintz et al, 2003).
Therefore, it is evident that MRI has the potential to miss osteochondral lesions. This may be related to the relative thickness of the image slices (usually 3mm taken at 1mm intervals) to the thickness of the talar cartilage (0.4 – 2.1mm) (Rolf et al, 2006).
TREATMENT OF OSTEOCHONDRAL LESIONS
The information presented below is adapted from two review studies on the treatment of osteochondral lesions. The first is a systematic review by Zengerink et al (2010) and the second is a review article by O’Loughlin et al (2010).
Now this is the upsetting part for us sports physiotherapists. The evidence seems to suggest that conservative management (a poorly defined term) is frequently ineffective in the management of osteochondral lesions. Zengerink et al (2010) showed overall successful outcomes in only approximately 45% of patients treated conservatively.
Treatment goals in conservative management are:
- Rest from aggravating activites
- Symptomatic relief, including NSAIDs.
- Restoration of ROM, strength and proprioception.
Surgical management, fortunately, is more successful than conservative management. However, the challenging thing about reviewing the evidence regarding the efficacy of surgical management is that there are:
- A large number of surgical techniques
- Homogeneity in the study groups
- Different techniques utilised for the varying classifications
- Few quality clinical trials
Therefore, given the above facts, that this article is becoming quite a monster (sorry guys!), and that surgical technique is never our choice to make, I will simply list the options and the weighted success rates (given as a percentage) from the systematic review (Zengerink et al, 2010).
- Excision – 54%
- Excision and Curettage – 77%
- Excision, Curettage and Bone Marrow Stimulation – 85%
- Autogenous Bone Graft – 61%
- Transmalleolar Drilling – 63%
- Retrograde Drilling – 88%
- Autologous Chondrocyte Implantation – 76%
- Osteochondral Autograft Transplantation – 87%
RETURN TO PLAY OUTCOMES
Now I’m sure this is what we (and our athletes) are really interested in. Rolf et al (2006) examined 61 consecutive athletes athroscopically (mostly debridement and excision) treated for osteochondral lesions and showed some promising results. At follow up between 12 and 24 months they found that 73% of athletes had return to play at the same level and 24% playing at lower levels. However, 36% of athletes had some ongoing issues with their ankle.
TAKE HOME MESSAGES
- There is a significant lack of high quality clinical trials on the subject of osteochondral lesions of the ankle!
- Osteochondral lesions are more common than you may think.
- Remember the key indicators: exertion pain, effusion, instability and joint line tenderness.
- Radiography should be utilised, but false negatives will occur.
- Your physiotherapy management will be effective in approximately 45% of cases.
- Surgical can provide good outcomes, and allow RTP at an elite level.
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Elias I, Zoga AC, Morrison WB, Besser MP, Schweitzer ME, Raikin SM. Osteochondral lesions of the talus: localization and morphologic data from 424 patients using a novel anatomical grid scheme. Foot Ankle Int. 2007;28(2):154-161
Fong DT, Hong Y, Chan LK, Yung PS, Chan KM. A systematic review on ankle injury and ankle sprain in sports. Sports Med. 2007;37(1):73-94
Joshy S, Abdulkadir U, Chaganti S, Sullivan B, Hariharan K. Accuracy of MRI scan in the diagnosis of ligamentous and chondral pathology in the ankle. Foot and Ankle Surgery 2010;16:78–80
Mintz DN, Tashjian GS, Connell DA, Deland JT, O’Malley M, Potter HG. Osteochondral lesions of the talus: a new magnetic resonance grading system with arthroscopic correlation. Arthroscopy. 2003;19(4):353-359.
O’Loughlin PF, Heyworth BE, Kennedy JG. Current Concepts in the Diagnosis and Treatment of Osteochondral Lesions of the Ankle. Am J Sports Med
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Zengerink M, Struijs PAA, Tol JL, van Dijk CN. Treatment of osteochondral lesions of the talus: a systematic review. Knee Surg Sports Traumatol Arthrosc 2010;18:238–246