Anterior interval arthrofibrosis is the condition of abnormal scarring in the 'anterior interval' - the space below the kneecap and behind the patellar tendon.
Page updated June 2023 by Dr Sheila Strover (Clinical Editor)
A normal anterior interval allows free movement of the fat pad, meniscus and patellar tendon.
Arthrofibrosis may 'gum' down mobile tissues, including the anterior interval, with adhesions, with consequent reduced range of motion of the knee.
The pain of anterior interval arthrofibrosis
Patellar mobilisation exercises performed early in the knee rehabilitation programme may break any adhesions before the tissue matures into proper scar tissue.
Once the anterior interval is stuck down with arthrofibrosis any effort to bend the knee results in excruciating pain. This may surprise patient and therapist and result in the patient being pushed ever harder to re-gain range of motion - a vicious cycle...
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Quote from peer-reviewed paper:
"....the functional consequences of joint fibrosis can severely limit patient quality of life and challenge healthcare professionals....Many risk factors for the development of AF are outside of control by both the patient and surgeon; therefore, early postoperative motion should be encouraged whenever possible...."
Citation: Lee DR, Therrien E, Song BM, Camp CL, Krych AJ, Stuart MJ, Abdel MP, Levy BA. Arthrofibrosis Nightmares: Prevention and Management Strategies. Sports Med Arthrosc Rev. 2022 Mar 1;30(1):29-41. doi: 10.1097/JSA.0000000000000324. PMID: 35113841; PMCID: PMC8830598.
The procedure of anterior interval release
If physiotherapy proves insufficient to release the patella, it may be necessary to do a surgical anterior interval release to free the scar tissue.
Under anaesthesia, the surgeon will introduce radiofrequency instruments into the knee cavity, passing the instrument down under the intermeniscal ligament and into the area behind the patellar tendon. When the instrument is turned on, the adhesions 'melt'.
Other relevant material -
- Adhesions
- Anterior interval
- Patellar mobilisations
- Anterior interval release
- Patella baja
- Range of motion
Discussion -
2006 - Anterior interval release - the rationale behind this surgical procedure - by Dr Peter J Millett (Knee Surgeon)
Peer-reviewed articles -
- 2004 - Arthroscopic Treatment of the Arthrofibrotic Knee - published paper summarised by Dr Sheila Strover (Clinical Editor)
- 2003 - Rehabilitation of the arthrofibrotic knee - Authors: Millett PJ et al. and summarised for you by Dr Sheila Strover (Clinical Editor)
- 1999 - Joint debridement and soft tissue release as a salvage procedure for the severely arthrofibrotic knee - Authors: Millett PJ et al. and summarised for you by Dr Sheila Strover (Clinical Editor)
- 1982 - Arthroscopic treatment of postoperative knee fibroarthrosis - published paper summarised by Dr Sheila Strover (Clinical Editor)