SLR - October 2015 - Merrell Kauwe

The Scarf Osteotomy with Minimally Invasive Lateral Release for Treatment of Hallux Valgus Deformity

Reference: Bock P, Kluger R, Kristen KH, Mittlbock M, Schuh R, Trnka HJ.  The Scarf Osteotomy with Minimally Invasive Lateral Release for Treatment of Hallux Valgus Deformity: Intermediate and Long-Term Results. J Bone Joint Surg Am. 2015 Aug 5;97(15):1238-45.

Reviewed By: Merrell Kauwe, DPM
Residency Program: Trinity Regional Medical Center

Podiatric Relevance: Hallux valgus is a frequently treated pathology amongst foot and ankle surgeons. There is a paucity of studies observing long term outcomes with surgical treatment. The authors present long term follow-up of the SCARF osteotomy for hallux valgus correction at Danube Hospital in Vienna, Austria.

Methods: A retrospective cohort study was carried out at Danube Hospital in Vienna, Austria. For methodological reasons, only unilateral surgical patients were included in the study. All patients underwent a SCARF osteotomy with a medial skin incision and fixation via a single compression screw.  Medial capsulorraphy was performed on all patients. Data analysis included comparison of pre and post-operative radiographic findings assessing hallux valgus angle (HVA), 1-2 inter-metatarsal angle (IMA), distal metatarsal articular angle (DMAA), and the position of the tibial sesamoid. The AOFAS hallux metatarsophalangeal-interphalangeal scale, VAS pain rating, and FAOS outcome score for hallux valgus were all used to for pre and post-operative comparisons. Post-operative complications were recorded.  Recurrent hallux valgus defined as angle greater than 20 degrees.

Results: Ninety-three patients with 93 feet met inclusion criteria with an average follow-up duration of 124 months (110-140). Mean age at time of surgery was 50 years (21-78) with 87 female patients and six male patients. Nineteen of the patients required Akin osteotomy secondary to interphalangeal deformity.    

All radiographic parameters showed statistically significant improvement at final follow up. HVA recurrence rate was 30 percent (28/93 feet). The median AOFAS scores improved from 57 points pre-operatively to a final median of 95 points. The total AOFAS score, pain sub-score, and alignment sub-score were positively correlated to post-operative HVA at final follow up. Preoperative average VAS of 6.3 improved to 0.4 at final follow up. VAS score was positively correlated to postoperative HVA with more pain reported with higher final HVA. FAOS was evaluated in 85 feet with patient reported pain showing significant correlation to final HVA.

Conclusions:  Nearly one-third of the observed feet showed recurrence of HVA greater than 20 degrees. Higher postoperative HVA was correlated to higher levels of pain. The pre-operative values correlated to recurrence rates include a HVA ≥30° and an IMA of ≥18°.  Recurrence takes place with the first 1.5-2.8 years. Higher hallux valgus angles both pre-operatively and at six weeks increase risk of recurrence. Higher values of IMA, DMAA, and sesamoid position at the six week mark are risk factors for recurrence.

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