Finite element method based parametric study of Gastrocnemius-soleus recession: implications to the treatment of midfoot-forefoot overload syndrome.

Gastrocnemius-soleus recession has been used to treat midfoot-forefoot overload syndrome and plantar fasciitis induced by equinus of the ankle joint. A controlled and selective amount of recession is imperative to maintain muscle strength and stability. The objective of this study was to conduct a parametric study to quantify the relationship between the level of recession and plantar fascia stress. A finite element model of the foot-ankle-shank complex was reconstructed from magnetic resonance and computed tomography images of a 63-year-old normal female. The model was validated by comparing modeled stresses to the measured plantar pressure distribution of the model participant during balanced standing. The midstance and push-off instants of walking stance were simulated with different levels and combinations of gastrocnemius-soleus recession resembled by different amounts of muscle forces. Halving the muscle forces at midstance reduced the average plantar fascia stress by a quarter while reducing two-third of the muscle forces at push-off reduced the average fascia stress by 18.2%. While the first ray of the plantar fascia experienced the largest stress among the five fasciae, the stress was reduced by 77.8% and 16.9% when the load was halved and reduced by two-third at midstance and push-off instants, respectively. Reduction in fascia stress implicates a lower risk of plantar fasciitis and other midfoot-forefoot overload syndromes. The outcome of this study can aid physicians to determine the amount of gastrocnemius-soleus recession towards patients with vdifferent levels of plantar fascia overstress. A detailed three-dimensional modelling on the plantar fascia is warranted in future study.

Macroscopic changes in sural nerve after gastrocnemius recession: a cadaver study.

BACKGROUND: Gastrocnemius recession is a common foot and ankle procedure and various techniques that have been utilized are mainly delineated by the anatomic position of the gastrocnemius transection; the 2 common ones are the Baumann and Strayer procedure. Both can adversely affect the sural nerve. The objective of this study was to evaluate the macroscopic changes in the sural nerve following gastrocnemius recession, and to compare the efficacy of the two procedures, regarding the improvement of maximal ankle dorsiflexion. METHODS: Ten fresh-frozen, above knee cadaveric legs were assigned to one of two gastrocnemius recession techniques: Baumann (n = 5) or Strayer (n = 5). A goniometer was used to measure degree of ankle dorsiflexion before and after the surgery. The sural nerve was meticulously dissected and marked with two suture knots, 2 cm apart. The ankle was passively dorsiflexed from 90° to maximal dorsiflexion in 5° degree increments, and the distance between two suture knots was measured at each increment. The distance between the two cut ends of gastrocnemius muscle was measured with the ankle at 90° and at maximal dorsiflexion. RESULTS: Overall, a mean increase in length between the suture knots on the sural nerve was 0.2 cm, from 90° to maximum ankle dorsiflexion (130°); both the Baumann and Strayer techniques resulted in 0.2 cm increase. The mean improvement in maximal ankle dorsiflexion in the Baumann and Strayer group was 22.6° and 22°, respectively. The mean change in distance between the two cut ends of the gastrocnemius muscle in the Baumann and Strayer group was 1.0 cm and 0.9 cm, respectively. CONCLUSION: Increased dorsiflexion of the ankle following Strayer or Baumann gastrocnemius recession resulted in similar macroscopic change in the sural nerve, which may contribute to the development of sural neuritis. Further clinical studies are warranted to assess clinical implications of these findings.

Gastrocnemius Recession in the Setting of Metatarsalgia: The Baumann Procedure.

A fundamental etiologic component of metatarsalgia is the repetitive loading of a locally concentrated force in the forefoot during gait. In the setting of an isolated gastrocnemius contracture, weight-bearing pressure is shifted toward the forefoot. If metatarsalgia is considered an entity more than a symptom, evaluation of gastrocnemius contracture must be a part of the physical examination, and gastrocnemius recession via the Baumann procedure alone, or in combination with other procedures, considered as an alternative treatment in an attempt to restore normal foot biomechanics.

Mid-term Results of Intramuscular Lengthening of Gastrocnemius and/or Soleus to Correct Equinus Deformity in Flatfoot.

BACKGROUND: Intramuscular lengthening of the gastrocnemius and/or soleus (Baumann procedure) is widely used in patients who have cerebral palsy, with several advantages over other lengthening techniques. Tightness of the gastrocnemius or gastrocnemius-soleus complex has been confirmed to be related to flatfoot deformity. The purpose of this study was to evaluate the mid-term results of the Baumann procedure as a part of the treatment of flatfoot with equinus deformity. METHODS: We reviewed 35 pediatric and adult patients (43 feet) with flatfoot who underwent the Baumann procedure for the concomitant equinus deformity. The mean duration of follow-up was 39.4 months. Preoperative and follow-up evaluations included the maximal angle of dorsiflexion of the ankle with the knee fully extended and with the knee flexed to 90 degrees, the American Orthopaedic Foot & Ankle Society ankle-hindfoot (AOFAS-AH) scores, and postoperative complications. RESULTS: Preoperatively, the mean angle of passive ankle dorsiflexion with the knee extended was -4.7 ± 2.7 degrees and that with the knee flexed was 2.3 ± 2.5 degrees. At the final follow-up, both values improved significantly by a mean of 13.6 degrees (P < .001) and 9.7 degrees (P < .001), respectively. The average AOFAS-AH scores improved from 56.8 points preoperatively to 72.1 at the final follow-up. Recurrence of equinus was observed in 3 patients (4 feet). There were no cases of overcorrection, neurovascular injury, or healing problems. CONCLUSIONS: Our results indicate that the Baumann procedure can effectively and sequentially correct the tightness of the gastrocnemius or the gastrocnemius-soleus complex in patients with flatfoot deformity, without obvious postoperative complications. LEVEL OF EVIDENCE: Level IV, retrospective case series.