Anterior knee pain syndrome (AKPS) is one of the most common musculoskeletal disorders. Functional hallux limitus (FHL) is a loss of metatarsophalangeal joint extension during terminal stance and it induces a sagittal plain blockade. The stability mechanisms of the foot are disrupted with consequences especially in the knee. The aim of our study was to establish a causative relationship between FHL and AKPS and present a new treatment strategy for the AKPS.

We prospectively studied a group of patients with AKPS and FHL treated with endoscopic tenolysis of the Flexor Hallucis Longus (FHL) tendon. Inclusion criteria were failed conservative treatment for the AKPS and positive Stretch test for the diagnosis of FHL. Patients with known posture and gait pathology were excluded. A matched cohort of patients treated successfully conservatively for AKPS were used as control group. All the patients of the study group had an arthroscopic release of the FHL tendon. Gait analysis performed before and after the operation focused on static, postural and dynamic parameters. Clinical questionnaires were used prospectively pre and postoperatively. Statistical analysis was performed with SPPS for Mac (P<0.05).

Twenty-five patients were included in our study group (m/f – 36/64%). The mean age was 35 years old (range 18–65). There were no complications encountered postoperatively and all the patients were able to weight bear from day 1. Patello-femoral pain was found only in 20% of patients postoperatively as compared to 100% preoperatively (P<0.05). The area of pressure under the first metatarsal head was statistically significantly increased after the operation (P<0.05). The average pressure under the tip of the Hallux was statistically significantly lower in all patients after the FHL tenolysis. The time of support under the head of the first metatarsal head in dynamic conditions did significantly increase following the operation. (P<0.05). Based on the Euroqol scores 85% of patients reported very good and excellent results postoperatively. (P<0.05).

FHL can be considered as a factor implicated in the pathogenesis of AKPS. Static and postural analysis showed a postoperative restoration of the functional anatomy of the forefoot. Postoperative clinical improvement, patient satisfaction and return to previous activities were good and excellent in more than 80%.

Arthroscopic release can be considered as an efficacious and safe treatment providing satisfactory results. Additional research studies with larger population groups are warranted.