SLR - October 2015 - Lara Whitford

Scarf-Akin Osteotomy for Hallux Valgus in Juvenile and Adolescent Patients

References: Agrawal Y, Bajaj SK, Flowers MJ.  Scarf-Akin Osteotomy for Hallux Valgus in Juvenile and Adolescent Patients. J Pediatr Orthop B. 2015 Nov; 24(6): 535-40.

Scientific Literature Review

Reviewed By: Lara Whitford, DPM
Residency Program: SUNY Downstate

Podiatric Relevance: This investigation presents outcomes of a commonly performed procedure by podiatric surgeons of juvenile and adolescent patients.
    
Methods: A retrospective study of adolescent patients who underwent surgery for symptomatic hallux valgus between February 2001 and 2010 was performed. All surgeries were done at a tertiary referral children’s hospital by or under supervision of the senior author. A total of 29 females were included and 18 patients underwent bilateral osteotomies. Inclusion criteria: juvenile hallux valgus were considered before age 10 and adolescent hallux valgus between ages 10-16. Exclusion criteria: patients with history of trauma, previous surgery, treated non-operatively, or known neuromuscular disorders. Five patients were excluded from analysis because they underwent surgery after the age of 16.

All patients underwent a Scarf-Akin bunionectomies. The Scarf osteotomy site was stabilized using two Barouk screws and the Akin osteotomy was stabilized with an 8mm staple. All patients were placed in a forefoot plaster cast for six weeks. Patients were followed at three, six, and 12 months post-operatively. Data collected for this study included age of diagnosis, age at first operation and those with recurrence, age at recurrence and revision surgery.  American Orthopaedic Foot and Ankle scores (AOFAS) of hallux valgus of the patients were done for objective clinical and functional assessment. Three patients were unable to be contacted for AOFAS scoring. Radiological assessment utilizing standardized technique included the intermetatarsal angle (IMA), hallux valgus angle (HVA), distal metatarsal articular angle (DMAA), interphalangeal angle (IPA), and the ratio of the length of the first to second metatarsal. The radiological findings were assessed by two authors independent of the senior author.

A patient was considered to have recurrence when  there was symptoms of swelling of the medial aspect of MTPJ, an inability to wear sportswear or fashionable footwear, or recurrence  with radiological parameters of IMA >9 and HVA >15 post-operatively after minimum of 6 months. Statistical analysis was done using the paired standard t-test for normal distributed data and the two-sample Wilcoxon test for non-normal distributed data. Statistical significance was defined as having a P value of 0.05 or less.

Results: The mean age of patients was 11.7 years at diagnosis and 12.7 years at surgery. 22 patients had no recurrence after a period of 32 months following surgery. Patients with no recurrence had improved IMA with mean 6.7 degrees, HVA mean of 11.6 degrees, DMMA mean of 9.4 degrees, and IPA of 12.1 degrees. The average AOFAS score was 97.8/100.

Ten patients had recurrence after a period of 27.6 months after surgery. All radiologic angles improved after surgery but recurrence of deformity was determined by radiographs. The HVA had highest positive predictive value as an indicator of recurrence with the mean increased from 18.4 degrees postoperatively to mean of 31.4 degrees. The HVA had t-value of -5.182 and P value of < 0.0001. The DMMA, IPA and MT maintained normal range. The AOFAS score was 93.6/100.

Seven patients had recurrence and revisional surgery, and this surgery was 26.3 months after the primary surgery. Satisfactory corrections were achieved in the radiological angles. Three patients had further symptoms after 26.6 months after their revision. One patient required a second revision at 28 months after her first revision. AOFAS score was 96.2/100.

One-hundred percent bone union rate with no osteotomy displacement was seen in this study. No statistical significance in DMAA, IPA and ratio of metatarsal lengths was seen between the groups. No statistical significance between the groups on the pain and alignment or AOFAS scores.

Conclusions: The Scarf-Akin osteotomy should only be considered for skeletally immature foot where there is progressive and painful deformity. Patients should be aware of risks of surgery and likelihood of revisional surgery. From this study, the osteotomy should be delayed until skeletal maturity in adolescent hallux valgus. Limitations of this study include: radiographs were only taken at six weeks postoperatively and taken only again if clinically indicated and intra-observer and inter-observer reliability was not assessed, measurements were recorded with consensus, and AOFAS scores were not at a fixed time postoperatively.

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