Contribution of various forefoot areas to push-off peak at different speeds and slopes during walking.

BACKGROUND: Push-off during the terminal stance phase has a major impact on forward progression during walking. During this phase, the ground reaction force is applied to a small area under the forefoot. A better understanding of how single forefoot areas contribute to push-off peak in healthy subjects is needed to develop biomimetic orthopedic devices for forefoot amputees. RESEARCH QUESTION: What is the contribution of different forefoot sole areas to push-off peak as a function of speed and slope? METHODS: In this analytical study, 15 healthy subjects walked on a treadmill at different speeds (0.8 m/s; 1.2 m/s; 1.6 m/s; max. gait speed) without de-/inclination and on different slopes (-10°; -5°; 0°; 5°; 10°) with normal walking speed. The Novel Pedar-X System was used to measure vertical sole force. Push-off peak of the entire sole was determined and relative contributions of the areas under the hallux, first ray, and toes (I-V) were calculated and analyzed using separate repeated-measures ANOVA (α = 0.05). RESULTS: Push-off peak increases with faster walking speeds as well as with 10° inclination. Downhill walking is associated with a reduced push-off peak. The contribution of all forefoot areas increases with faster walking speeds and at a declination of -10°. Push-off contribution of the area under the hallux increases by about 64.6% at fast walking compared to slow walking and this increase is higher than that of the area under the first ray and toes (p < 0.05). SIGNIFICANCE: These findings indicate the major role of the hallux in speed generation and the importance of the forefoot during downhill walking. The results show the need for an adequate assistive device even in hallux amputation cases to compensate for deficits in the push-off phase.

Predictors of delayed wound healing after simultaneous endovascular treatment and minor forefoot amputation for chronic limb-threatening ischemia with wound infection.

OBJECTIVES: To assess wound healing after simultaneous endovascular treatment (EVT) and minor forefoot amputation and identify the predictors of delayed wound healing in patients with chronic limb-threatening ischemia (CLTI) and bacterial infections of the wounds. METHODS: In this single-center retrospective cohort study, we evaluated 79 consecutive limbs with tissue loss from 73 CLTI patients who underwent simultaneous EVT and minor forefoot amputation between November 2017 and May 2020. To estimate the rate of wound healing after the simultaneous procedure, we used the Kaplan-Meier method. To assess the association between baseline characteristics and delayed wound healing, we used the Cox proportional hazard model. RESULTS: All patients who underwent the simultaneous procedure had ischemic wounds with bacterial infection. The rate of wound healing at 6 months reached 82%. The median time for wound healing was 76 days. According to multivariable analysis, Lisfranc/Chopart amputation (hazard ratio (HR) 2.46, 95% confidence interval (CI) 1.09-6.60), absence of above-the-knee (ATK) occlusive lesions (HR 1.89, 95% CI 1.04-3.45), and poor below-the-ankle (BTA) runoff (HR 1.77, 95% CI 1.01-3.11) were independent predictors of delayed wound healing. CONCLUSION: Lisfranc/Chopart amputation, absence of ATK occlusive lesions, and poor BTA runoff were independent predictors of delayed wound healing after simultaneous EVT and minor forefoot amputation in patients with CLTI and bacterial infections of the wound.

Analysis of repeated lesions after diabetic forefoot amputation.

AIM: This study was performed to analyze the clinical characteristics, related factors, and prognosis of repeated lesions after diabetic forefoot amputation. METHODS: The medical records of 998 patients who underwent forefoot amputation because of their diabetic feet from March 2002 to February 2021 were retrospectively analyzed. Of the 508 selected patients with a follow-up period of at least 6 months, 288 had repeated lesions in the forefoot, and 220 did not have repeated lesions. The related factors of repeated lesions were compared and analyzed. Of the patients with repeated lesions, 142 and 104 on the ipsilateral and contralateral sides, respectively were also compared and examined. RESULTS: Repeated lesions were statistically significant in diabetic polyneuropathy, vascular calcification, and dialysis. However, the anatomical positions of diabetic foot lesions, causes of lesions, anatomical amputation levels, number of surgeries, and management duration had no significant differences. Contralateral lesions occurred 8 months later than ipsilateral lesions, but reamputation above the Lisfranc joint was more frequent and prognosis was poorer. CONCLUSIONS: Repeated lesions were affected by general conditions, and the contralateral side must be carefully examined after diabetic forefoot amputation.

Predictive value of forefoot plantar pressure to predict reulceration in patients at high risk.

AIMS: To analyze a plantar pressure cut-off point for diabetic foot reulceration beneath the metatarsal heads in patients with previous forefoot amputation. METHODS: A one-year prospective study was conducted in a total of 105 patients at high risk for foot ulceration. Peak plantar pressure (PPP) and pressure-time integral (PTI) in the entire foot, the forefoot region, and each metatarsal head separately were registered. ROC curves were used to select the optimal diagnostic pressure cut-off points. Patients were follow-up monthly or until the development of an ulcer event. RESULTS: A total of 52 (49.5%) patients developed a reulceration. Using ROC analyses for PPP in the full-foot and in the forefoot, did not predict reulceration beneath the metatarsal heads. Analyzing separately each metatarsal head all patients with values greater than or equal to 20.8 N/cm2 at the 1st, 18.62 N/cm2 for the 2nd, 18.85 at the 3rd, 17.88 at the 4th, and 12.2 at the 5th metatarsal heads will suffer a reulceration despite the use of orthopedic treatment with optimum values of sensitivity (from 100 to 87.5) and specificity (from 83.2 to 62.8). CONCLUSION: Barefoot pressures beneath the metatarsal heads should be analyzed separately to predict the region at risk of reulceration.

A Comparison of Adverse Short-Term Outcomes Following Forefoot Amputation Performed on an Inpatient Versus Outpatient Basis.

The objective of this investigation was to evaluate short-term adverse outcomes following forefoot amputation with a specific comparison between those procedures performed on an inpatient versus outpatient basis. The 2018 American College of Surgeons National Surgical Quality Improvement Program database was interrogated to select those subjects with a 28805 current procedural terminology code (amputation, foot; transmetatarsal) that underwent the procedure with "all layers of incision (deep and superficial) fully closed." This resulted in 326 subjects who underwent the procedure on an inpatient basis and 72 subjects who underwent the procedure on an outpatient basis. Results of the primary outcome measures found no significant differences between groups with respect to the development of a superficial surgical site infection (5.8% vs 5.6%; p = .950), deep incisional infection (3.4% vs 5.6%; p = .380), or wound disruption (3.4% vs 6.9%; p = .163). Additionally, no significant differences were observed between groups with respect to unplanned reoperations (15.6% vs 12.5%; p = .500) or unplanned hospital readmissions (21.8% vs 23.6%; p = .957). The results of this investigation demonstrate no difference in short-term adverse outcomes following the performance of forefoot amputation with primary closure when the procedure is performed on an inpatient or outpatient basis. We hope that this information is utilized in future investigations specifically examining this clinical scenario as it relates to hospital admission criteria related to lower extremity tissue loss, length of hospital stay considerations, the timing of partial foot amputation following revascularization, and the economics of limb preservation.

Long-term results after internal partial forefoot amputation (resection): a retrospective analysis.

INTRODUCTION: Internal partial forefoot amputation (IPFA) is a treatment option for osteomyelitis and refractory and recurrent chronic ulcers of the forefoot. The aim of our study was to assess the healing rate of chronic ulcers, risk of ulcer recurrence at the same area or re-ulceration at a different area and revision rate in patients treated with IPFA. MATERIALS AND METHODS: All patients who underwent IPFA of a phalanx and/or metatarsal head and/or sesamoids at our institution because of chronic ulceration of the forefoot and/or osteomyelitis from 2004 to 2014 were included. Information about patient characteristics, ulcer healing, new ulcer occurrence, and revision surgery were collected. Kaplan-Meier survival curves were plotted for new ulcer occurrence and revision surgery. RESULTS: A total of 102 patients were included (108 operated feet). 55.6% of our patients had diabetes. In 44 cases, an IPFA of a phalanx was performed, in 60 cases a metatarsal head resection and in 4 cases an isolated resection of sesamoids. The mean follow-up was 40.9 months. 91.2% of ulcers healed after a mean period of 1.3 months. In 56 feet (51.9%), a new ulcer occurred: 11 feet (10.2%) had an ulcer in the same area as initially (= ulcer recurrence), in 45 feet (41.7%) the ulcer was localized elsewhere (= re-ulceration). Revision surgery was necessary in 39 feet (36.1%). Only one major amputation and five complete transmetatarsal forefoot amputations were necessary during the follow-up period. Thus, the major amputation rate was 0.9%, and the minor amputation rate on the same ray was 13.9%. CONCLUSIONS: IPFA is a valuable treatment of chronic ulcers of the forefoot. However, new ulceration is a frequent event following this type of surgery. Our results are consistent with the reported re-ulceration rate after conservative treatment of diabetic foot ulcers. The number of major amputations is low after IPFA. LEVEL OF EVIDENCE: Retrospective Case Series Study (Level IV).

Revision After Total Transmetatarsal Amputation.

Total transmetatarsal amputation (TMA) can be an option for foot salvage in gangrene, sepsis, or infected necrosis. However, the literature concerning predictive outcome factors and bacterial sampling is scarce. To identify potential associations between revision surgery and underlying bacteria or other preoperative selection criteria, we reviewed all patients with TMA who were treated at our institution. We compared the patients with remissions with surgical revisions. Among 96 adult patients with TMA (105 amputations), 42 required a revision surgery (40%), 18 had a further minor proximal surgical reamputation (17%) and 18 had a major proximal surgical reamputation (14%). In group comparisons, a previous infection with Staphylococcus aureus was protective with a lower revision risk (4/26 with revision surgery vs 22/26 without revisions; p = .03). This was the opposite for postoperative persistent soft tissue or bone infections (p < .01) and delayed wound healing (p < .01), which were positively associated with a revision risk. The American Society of Anesthesiologists Score, sex, age, body mass index, diabetes, polyneuropathy, chronic renal failure, dialysis, peripheral arterial disease, smoking status, and antibiotic regimen did not influence this revision risk. These results must be interpreted cautiously because no multiple variable calculations could be conducted as a result of the paucity of cases and confounding could not be evaluated sufficiently. TMA is an option to prevent major amputations, but it may be associated with a subsequent revision risk of 40% in adult patients. In our cohort study, persistent postamputation infection and delayed wound healing were associated with revision. However, no preoperative selection criteria were found that lead to revision surgery except for an infection with Staphylococcus aureus, which protected against revision surgery.