Druckverteilungsmessung nach Scarf-Osteotomie bei Hallux valgus

Inverted Z-scarf osteotomy for hallux valgus deformity correction: intermediate-term results in 55 patients

The Z-scarf osteotomy is used for hallux valgus deformity correction by foot and ankle surgeons worldwide. Inverting the Z-scarf osteotomy configuration strengthens the construct in both sawbone and cadaver models, but clinical results of this configuration have not been reported in the literature. This retrospective study evaluates the subjective and intermediate-term postoperative radiographic results of 73 inverted Z-scarf osteotomy procedures for hallux valgus correction in 55 patients from January 1994 to December 2003. The modified University of Maryland 100-Point Painful Foot Center Scoring System demonstrated 52 patients (95%) with good to excellent results at a mean follow-up of 5 years (range 2-11 years). Radiograph measurements revealed the following: first-second intermetatarsal angle mean, 6.1° (range 2-14°), average reduction 4.6°; hallux abductus angle mean, 11.0° (range -8-30°), average reduction 10.1°; tibial sesamoid position mean, 2.3; first metatarsal protrusion distance mean, -2.1 mm. Two patients (2 of 73 feet) developed major complications: one progressed to clinically acceptable hallux varus; another sustained compromise of one fixation screw with minor displacement at the distal osteotomy that healed in satisfactory position after non-weight-bearing immobilization. There were no cases of osteonecrosis, delayed union, or nonunion. The inverted Z-scarf osteotomy, with advantages in both mechanical strength and technique of execution over the traditional configuration, demonstrates high patient satisfaction, restoration of normal radiographic parameters, and a low complication rate in this study.

Rehabilitation after hallux valgus surgery: importance of physical therapy to restore weight bearing of the first ray during the stance phase

BACKGROUND

Operative treatment of people with hallux valgus can yield favorable clinical and radiographic results. However, plantar pressure analysis has demonstrated that physiologic gait patterns are not restored after hallux valgus surgery.

OBJECTIVE

The purpose of this study was to illustrate the changes of plantar pressure distribution during the stance phase of gait in patients who underwent hallux valgus surgery and received a multimodal rehabilitation program.

DESIGN

This was a prospective descriptive study.

METHODS

Thirty patients who underwent Austin (n=20) and scarf (n=10) osteotomy for correction of mild to moderate hallux valgus deformity were included in this study. Four weeks postoperatively they received a multimodal rehabilitation program once per week for 4 to 6 weeks. Plantar pressure analysis was performed preoperatively and 4 weeks, 8 weeks, and 6 months postoperatively. In addition, range of motion of the first metatarsophalangeal joint was measured, and the American Orthopaedic Foot and Ankle Society (AOFAS) forefoot questionnaire was administered preoperatively and at 6 months after surgery.

RESULTS

The mean AOFAS score significantly increased from 60.7 points (SD=11.9) preoperatively to 94.5 points (SD=4.5) 6 months after surgery. First metatarsophalangeal joint range of motion increased at 6 months postoperatively, with a significant increase in isolated dorsiflexion. In the first metatarsal head region, maximum force increased from 117.8 N to 126.4 N and the force-time integral increased from 37.9 N.s to 55.6 N.s between the preoperative and 6-month assessments. In the great toe region, maximum force increased from 66.1 N to 87.2 N and the force-time integral increased from 18.7 N.s to 24.2 N.s between the preoperative and 6-month assessments.

LIMITATIONS

A limitation of the study was the absence of a control group due to the descriptive nature of the study.

CONCLUSIONS

The results suggest that postoperative physical therapy and gait training may lead to improved function and weight bearing of the first ray after hallux valgus surgery.

Z-osteotomy in hallux valgus: clinical and radiological outcome after Scarf osteotomy

Correction osteotomies of the first metatarsal are common surgical approaches in treating hallux valgus deformities whereas the Scarf osteotomy has gained popularity. The purpose of this study was to analyze short- and mid-term results in hallux valgus patients who underwent a Scarf osteotomy. The subjective and radiological outcome of 131 Scarf osteotomies (106 hallux valgus patients, mean age: 57.5 years, range: 22-90 years) were retrospectively analyzed. Mean follow-up was 22.4 months (range: 6 months-5 years). Surgical indications were: intermetatarsal angle (IMA) of 12-23°; increased proximal articular angle (PAA>8°), and range of motion of the metatarsophalangeal joint in flexion and extension >40°. Exclusion criteria were severe osteoporosis and/or osteoarthritis. The mean subjective range of motion (ROM) of the great toe post-surgery was 0.8±1.73 points (0: full ROM, 10: total stiffness). The mean subjective cosmetic result was 2.7±2.7 points (0: excellent, 10: poor). The overall post-operative patient satisfaction with the result was high (2.1±2.5 points (0: excellent, 10: poor). The mean hallux valgus angle improvement was 16.6° (pre-operative mean value: 37.5°) which was statistically significant (p<0.01). The IMA improved by an average of 5.96° from a pre-operative mean value of 15.4° (p<0.01). Neither osteonecrosis of the distal fragment nor perioperative fractures were noted during the follow-up. In keeping with our follow-up results, the Scarf osteotomy approach shows potential in the therapy of hallux valgus.

Comparative mechanical testing of different geometric designs of distal first metatarsal osteotomies

BACKGROUND

The mechanical behavior of a newly described distal metatarsal osteotomy design in the shape of a reversed "L" was compared with the modified chevron and scarf osteotomies.

METHODS

Experiments were performed using full-sized Sawbone models (Sawbones Europe AB, Malmö, Sweden) of the first ray. Three groups consisting of 10 scarf, 10 modified chevron, and 10 reversed L osteotomies were investigated. All distal fragments were displaced 5 mm laterally without angulation. The proximal fragment of each specimen was embedded in an epoxy resin cylinder and positioned at 15 degrees inclination to the ground. The distal fragment was loaded by a dorsally directed vertical force which was applied at the sesamoid location under the metatarsal head. Load and displacement at failure, work to failure, site of failure and contact areas were recorded for each osteotomy.

RESULTS

Similar testing results were obtained in the reversed "L" and chevron osteotomies, while the scarf osteotomy needed almost 5 times less work to failure. In nine of 10 reversed "L" osteotomies and in all scarf osteotomies, the site of failure was at the proximal screw insertion site. The contact areas averaged 163 mm(2) for the reversed "L," 116 mm(2) for the chevron, and 270 mm(2) for the scarf osteotomy.

CONCLUSIONS

The reversed L osteotomy is a promising design combining the advantages of both the chevron and scarf osteotomies. Further investigations need to be performed to confirm its clinical utility.

The Mitchell and Scarf osteotomies for hallux valgus correction: a retrospective, comparative analysis using plantar pressures

A retrospective analysis was performed to describe the effects of Mitchell and Scarf osteotomies on plantar pressure distribution and their relevance to the clinical outcome. This study evaluated 28 patients who underwent operations for moderate to severe hallux valgus deformities over a period of 3 years at 2 different centers. Twenty-two Mitchell and 22 Scarf osteotomies were performed on 28 patients with a mean follow-up of 23 months (13-62 months). The average postoperative American Orthopaedic Foot and Ankle Society scores after Mitchell and Scarf osteotomies were 74 and 84, respectively. A control group of 15 individuals with 20 healthy feet were included for comparison. The plantar pressures were documented with the Musgrave footplate. The pressure distributions under the first metatarsal head were within normal limits in both study groups compared with the control group (P = .77). After Mitchell osteotomies, deficient load bearing was noted under the hallux (P = .007), coupled with overloading of the second and third metatarsal heads (P = .01). But after the Scarf procedures, increased weight bearing was noted at the heel (P = .04) and midfoot (P = .09), with better load distribution under the hallux. However, it was not comparable with the control group. Correlation of American Orthopaedic Foot and Ankle Society scores and pressure variables demonstrated a significant positive correlation with hallux loading (P = .001). This study demonstrates that adequate hallux loading is imperative for a better outcome of the procedure. Mitchell and Scarf osteotomies do not restore the load-bearing function of the foot to normal, whereas hallux loading plays an important role for a better outcome of the procedure.