Foot & Ankle International

Total joint surgeons have successfully performed hip, knee, and shoulder arthroplasty procedures in the outpatient setting without compromising safety, satisfaction, or results. The purpose of this study was to evaluate outpatient total ankle arthroplasty (TAA) as compared with overnight or extended inpatient stay, with regard to 90-day medical and operative complications, reoperations, readmissions or emergency room visits, and pain control.

The medical records of patients who underwent TAA with 1 fellowship-trained orthopedic foot and ankle surgeon were reviewed. Outcome measures included operative complications, adverse medical events, readmission or emergency room visit for any reason, or reoperation within 90 days following surgery; surgeon’s office contact before first postoperative visit regarding pain or other issues; visual analog scale pain score at the first postoperative visit; and need for narcotic refill. Outcomes were assessed by admission status: outpatient, overnight observation, or inpatient admission. Standard statistical analysis was used, and P < .05 was considered significant.

Eighty-one patients underwent TAA who met inclusion criteria, and 8 had a complication (10%). A significant difference in complication rate was seen among groups (P = .01) but not rate of readmission or reoperation. Of 16 patients, 5 (31%) who were admitted for 2 or more nights following surgery had a complication, as opposed to 3 of 65 (5%) who were outpatient or admitted overnight (P = .01). There were no differences in frequency of postoperative phone calls, narcotic refills, or visual analog scale pain scores at the first postoperative visit. There were no adverse medical events.

With proper instruction, TAA was performed safely in the outpatient setting. As health care policy continues to evolve in the United States, safe and efficient practices will remain a priority.

Level III, retrospective comparative study.

There remains little evidence to support a perioperative hemoglobin A_1c (HbA_1c) level that could serve as a threshold for a significantly increased risk of postoperative surgical site infection (SSI) following forefoot surgery.

A national database was queried for patients who underwent elective forefoot surgery with diabetes. Patients with a perioperative HbA_1c level within 3 months of surgery were identified and stratified based on HbA_1c level in 0.5 mg/dL increments. The incidence of SSI was determined by either a diagnosis or procedure for SSI within 1 year and a receiver operating characteristic (ROC) curve and area under the curve (AUC) analysis was performed to determine an optimal threshold value of HbA_1c.

A total of 4630 patients who underwent forefoot surgery with diabetes with a perioperative HbA_1c were included. The rate of SSI ranged from 2.3% to 11.8%. The inflection point of the ROC curve corresponded to an HbA_1c level above 7.5 mg/dL (P < .0001; 95% confidence interval [CI] = 0.58-0.67; AUC = 0.631; specificity = 75%; sensitivity = 46%). After multivariate analysis, patients with an HbA_1c level of 7.5 mg/dL or greater had a significantly higher risk for postoperative wound infection compared to patients below this threshold (OR = 1.92; 95% CI = 1.5-2.4; P < .0001).

The risk of postoperative SSI following forefoot surgery increased as the perioperative HbA_1c increased. ROC analysis determined that a perioperative HbA_1c above 7.5 mg/dL could serve as a threshold for a significantly increased risk of postoperative SSI following forefoot surgery.

Level III, comparative series.

Minimally invasive surgery is being used increasingly, including for hallux valgus surgery. Despite the growing interest in minimally invasive procedures, there have been few publications on percutaneous chevron/akin (PECA) procedures, and no studies have been published comparing PECA to open scarf/akin osteotomies (SA).

This was a prospective, randomized study of 50 patients undergoing operative correction of hallux valgus using one of 2 techniques (PECA vs open SA). Data were collected preoperatively and on 1 day, 2 weeks, 6 weeks, and 6 months postoperatively. Outcome measures include the American Orthopaedic Foot & Ankle Society Hallux-Metatarsophalangeal-Interphalangeal (AOFAS-HMI) Score, visual analog pain score, hallux valgus angle (HVA), and 1-2 intermetatarsal angle (IMA). Twenty-five patients underwent PECA procedures and 25 patients received SA procedures.

Both groups showed significantly improved AOFAS-HMI scores after surgery (PECA group: 61.8 to 88.9, SA group: 57.3 to 84.1, P = .560) with comparable final scores. HVA and IMA also presented similar outcomes at final follow-up (P = .520 and P = .270, respectively). However, the PECA group showed significantly lower pain level (VAS) in the early postoperative phase (postoperative day 1 to postoperative week 6, P < .001 and P = .004, respectively). No serious complications were observed in either group.

Both groups showed comparable good to excellent clinical and radiologic outcomes at final follow-up. However, the PECA group had significantly less pain in the first 6 weeks following surgery.

Level II, prospective comparative study.

Hallux valgus alters gait, compromising first ray stability and function of the windlass mechanism at the late stance. Hallux valgus correction should restore the stability of the first metatarsal. Comparative studies reporting the impact of different hallux valgus correction methods on gait are rare. We report the results of a case-control study between distal chevron osteotomy and first tarsometatarsal joint derotational arthrodesis (FTJDA).

Two previously studied hallux valgus cohorts were matched: distal chevron osteotomy and FTJDA. Seventy-seven feet that underwent distal chevron osteotomy (chevron group) and 76 feet that underwent FTJDA (FTJDA group) were available for follow-up, with a mean of 7.9 years (range, 5.8-9.4 years) and 5.1 years (range, 3.0-8.3 years), respectively. Matching criteria were the hallux valgus angle (HVA) and a follow-up time difference of a maximum 24 months. Two matches were made: according to the preoperative HVA and the HVA at late follow-up. Matching provided 30 and 31 pairs, respectively. Relative impulses (%) of the first toe (T1) and metatarsal heads 1 to 5 (MTH1-5), weightbearing radiographs, and American Orthopaedic Foot & Ankle Society (AOFAS) (hallux metatarsophalangeal-interphalangeal [MTP-IP]) scores were studied.

The relative impulse of MTH1 was higher in the FTJDA group, whereas a central dynamic loading pattern was seen in the chevron group. This result remained when relative impulses were analyzed according to the postoperative HVA. The mean difference in the HVA at follow-up was 6.2 degrees (95% confidence interval, 3.0-9.5; P = .001) in favor of the FTJDA group.

The dynamic loading capacity of MTH1 was higher in the FTJDA group in comparison to the chevron group. The follow-up HVA remained better in the FTJDA group.

Level III, case-control study.

This prospective study evaluated the intermediate-term outcomes of operatively treating primary osteochondral lesions of the talus (OLT) of 1.5 cm² or smaller with arthroscopic excision, microfracture, and allograft cartilage extracellular matrix (ECM).

Between 2012 and 2015, 30 consecutive patients received allograft cartilage ECM at their microfractured OLT of 1.5 cm² or smaller after failing nonoperative treatment. Preoperative and postoperative function and pain were graded using the Foot and Ankle Ability Measure (FAAM) and a visual analog scale (VAS), respectively. Postoperative imaging was assessed for osteochondral healing and degenerative changes. This included computed tomography (CT) at 6 months from surgery. Data regarding postoperative complications were recorded. All 30 patients that received allograft cartilage ECM for their OLT were evaluated for final follow-up at a mean of 20.2 months.

Mean FAAM increased from 51.4 preoperatively to 89.3 of 100 at final follow-up. Mean VAS decreased from 8.1 preoperatively to 1.7 of 10 at final follow-up. These differences between preoperative and postoperative function and pain were statistically significant (P < .05). At 6 months from surgery, 2 patients (6.7%) received CT scans that revealed incomplete chondral formation at their OLT. At 19 months after surgery, a separate patient (3.3%) developed ankle arthritic changes.

Treating OLTs with allograft cartilage ECM has not been previously reported. Using allograft cartilage ECM resulted in a high rate of improvement in ankle function and pain in patients with OLTs. These findings are important as allograft cartilage ECM could be of significant benefit for patients with OLTs.

Level III, prospective comparative series.

Calcaneal lengthening is used to correct symptomatic planovalgus foot deformity, but outcomes have been less satisfactory in children with cerebral palsy. This study aimed to define limits of calcaneal lengthening by analyzing the risk factors for undercorrection of deformity.

We retrospectively reviewed 20 cases of children with cerebral palsy who underwent calcaneal lengthening of 30 planovalgus feet at a mean age of 11.9 years. Foot deformities were evaluated by the anteroposterior talo–first metatarsal angle (normal, 10 ± 7.0 degrees), lateral talo–first metatarsal angle (normal, 13 ± 7.5 degrees), and lateral calcaneal pitch angle (normal, 17 ± 6.0 degrees) on standing foot radiographs. Among these parameters, a corrected foot was defined as 2 or 3 parameters being corrected to within a normal range, and an undercorrected foot was only 1 or no parameter being corrected to within a normal range. Factors were compared between the corrected group and undercorrected group for significant predictors, and cutoff values of predictors were calculated for use as a clinical guideline.

Seventeen planovalgus feet were corrected satisfactorily by calcaneal lengthening, while the other 13 feet were undercorrected. Undercorrected feet had a greater preoperative anteroposterior talonavicular angle (33.7 vs 22.8 degrees, P = .001) and a smaller lateral calcaneal pitch (−1.7 vs 5.6 degrees, P = .03). A talonavicular angle of more than 24 degrees and calcaneal pitch less than −5 degrees were identified as cutoff values using a receiver operating characteristic curve. The predicted probability of undercorrection was 100% (9/9 feet) for 2 positive predictors, 50% (8/16 feet) for 1 positive predictor, and 0 (0/5 feet) for zero predictors.

A talonavicular lateral subluxation of more than 24 degrees on the anteroposterior radiograph and a calcaneal pitch angle less than −5 degrees on the lateral radiograph were 2 independent predictors that could be used to identify a planovalgus deformity that would be beyond the corrective capacity of calcaneal lengthening to restore normal alignment.

Retrospective case control study, level III

The field of foot and ankle surgery lacks a widely accepted gold-standard patient-reported outcome instrument. With the changing infrastructure of the medical profession, more efficient patient-reported outcome tools are needed to reduce respondent burden and increase participation while providing consistent and reliable measurement across multiple pathologies and disciplines. The primary purpose of the present study was to validate 3 Patient-Reported Outcomes Measurement Information System computer adaptive tests (CATs) most relevant to the foot and ankle discipline against the Foot and Ankle Outcome Score (FAOS) and the Short Form 12 general health status survey in patients with 6 common foot and ankle pathologies.

Patients (n = 240) indicated for operative treatment for 1 of 6 common foot and ankle pathologies completed the CATs, FAOS, and Short Form 12 at their preoperative surgical visits, 1 week subsequently (before surgery), and at 6 months postoperatively. The psychometric properties of the instruments were assessed and compared.

The Patient-Reported Outcomes Measurement Information System CATs each took less than 1 minute to complete, whereas the FAOS took 6.5 minutes, and the Short Form 12 took 3 minutes. CAT scores were more normally distributed and had fewer floor and ceiling effects than those on the FAOS, which reached as high as 24%. The CATs were more precise than the FAOS and had similar responsiveness and test-retest reliability. The physical function and mobility CATs correlated strongly with the activities subscale of the FAOS, and the pain interference CAT correlated strongly with the pain subscale of the FAOS. The CATs and FAOS were responsive to changes with operative treatment for 6 common foot and ankle pathologies.

The CATs performed as well as or better than the FAOS in all aspects of psychometric validity. The Patient-Reported Outcomes Measurement Information System CATs show tremendous potential for improving the study of patient outcomes in foot and ankle research through improved precision and reduced respondent burden.

Level II, prospective comparative study.

The presence of nonunion of a talar fracture with displacement, together with complete avascular necrosis, is a challenging entity to treat.

Twelve patients, 8 men (66.7%) and 4 women (33.3%), with nonunited talar fractures and extensive avascular necrosis of the talus were included. The average age was 27.7 years (range, 19-38 years). After exclusion of infection, the patients underwent resection of necrotic bone, bulk autograft, and fusion using an intramedullary nail. The posterior approach was used in 11 patients and the anterior approach in 1 patient. The primary outcome was solid osseous union at the ankle and subtalar level and between the talar head anteriorly and the posterior construct, as evidenced by computed tomographic examination. Functional assessment was performed with the American Orthopaedic Foot & Ankle Society score and subjective patient satisfaction

After a mean follow-up duration of 23 months (range, 12-60 months), solid osseous union was achieved in 8 patients (66.7%). Stable fibrous union was seen in 1 patient (8.3%). Three patients (25%) required reoperation, and osseous fusion was finally achieved. American Orthopaedic Foot & Ankle Society score improved from a mean of 39.3 (range, 12-56) preoperatively to 76.6 (range, 62-86) at last follow-up. Subjective patient satisfaction was graded good or excellent in all cases.

Resection of necrotic talar body and bulk autograft with tibiotalocalcaneal fusion by an intramedullary nail through a posterior approach was a reasonable option for the management of type IV posttraumatic talar deformity.

Level IV, case series.

The flexibility of the first metatarsophalangeal (MTP) joint in patients with hallux rigidus (HR) has not been studied. Compared to measuring range of motion alone, measures of joint flexibility provide additional information that may prove useful in the assessment of HR. The purpose of this study was to assess the flexibility of the hallux MTP joint in patients with HR compared to controls using a novel flexibility device.

Fifteen patients with Coughlin stage II or III HR and 20 healthy controls were recruited prospectively. Using a custom flexibility jig, each of 2 raters performed a series of seated and standing tests on each subject. Dorsiflexion angle and applied torque were plotted against each other to generate 5 different parameters of flexibility. Differences between (1) HR patients and controls and (2) the sitting and standing testing positions were assessed with t tests. Intrarater test-retest reliability, remove-replace reliability, and interrater reliability were assessed with intraclass correlation coefficients (ICCs).

Patients in the HR group were older than patients in the control group (P < .001) and had lower maximum dorsiflexion (P < .001). HR patients were less flexible as measured by 3 of the 5 flexibility parameters: early flexibility (first 25% of motion; P = .027), laxity angle (P < .001), and torque angle (P = .002). After controlling for age, only laxity angle differed significantly between HR patients and controls (P < .001). Generally, patients were more flexible when seated compared to standing, with this effect being more marked in HR patients. All parameters had good or excellent intra- and interrater reliability (ICC ≥ 0.60).

Hallux MTP joint flexibility was reliably assessed in HR patients using a flexibility device. Patients with HR had decreased flexibility of the hallux MTP joint compared to control patients.

Level II, prospective comparative study.

Chronic diabetic foot wounds are a leading cause of amputation, morbidity, and hospitalization for patients with diabetes. Negative-pressure wound therapy (NPWT) can putatively facilitate wound healing, but the underlying mechanisms remain unclear. Cellular fibronectin (cFN) and transforming growth factor-β1 (TGF-β1) play an important role in wound healing. This prospective randomized controlled trial evaluated the effects of NPWT on the production of cFN and the expression of TGF-β1 in diabetic foot wounds of patients.

From January 2012 to January 2015, 40 patients with diabetic foot wounds were randomly and equally apportioned to receive either NPWT or advanced moist wound therapy (control) for 7 days. Granulation tissue was harvested before and after treatment. Immunohistochemistry and Western blot were performed to evaluate protein levels of cFN and TGF-β1, and real-time polymerase chain reaction (PCR) to measure corresponding mRNA expressions.

NPWT facilitated the expression of cFN and TGF-β1 in diabetic foot wounds. Immunohistochemical analysis revealed higher levels of cFN and TGF-β1 in the NPWT group than in the control group. Western blot and real-time PCR analysis further showed that protein and mRNA levels of cFN or TGF-β1 were higher in the NPWT group than that in the control group (P < .01, both).

Our results showed that NPWT facilitated the production of cFN and the expression of TGF-β1 in granulation tissue in diabetic foot ulcers.

Level I, randomized controlled study.

Using a total contact orthosis (TCO) is an effective method to offload in diabetic patients with foot neuropathy. However, the redistribution of peak plantar pressure is mostly observed during level walking, which may differ from other walking activities. The aim of this study was to investigate the plantar pressure from 4 regions of the foot during different walking activities (level walking, ramp ascending, ramp descending, stair ascending, and stair descending) in neuropathic diabetic patients with and without a TCO.

Sixteen neuropathic diabetic patients aged 40 to 60 years with calluses and hallux valgus were included in this study and were provided with TCOs made up of multifoam, Plastazote, and microcellular rubber. The plantar pressure and contact area with the TCO and without the TCO were recorded using the Pedar X system during different walking activities.

A significant reduction of plantar pressure during different walking activities at the toes and forefoot regions was observed while walking with the TCO compared with walking without the TCO (control condition). Plantar pressure increased at the midfoot region when walking with the TCO, and no significant difference was observed at the hindfoot region between the control and TCO conditions. Furthermore, maximum contact area was observed during level walking with the TCO compared with other walking activities.

The TCO significantly reduced and redistributed the peak plantar pressure from the sites where the ulceration rate is higher at the toes and forefoot compared with the other regions of the foot.

Therapeutic level II, lesser quality randomized controlled trial

Generalized joint laxity is often associated with gait deviations. The aim of this study was to investigate the static and dynamic loading pattern of the foot with increasing joint mobility and to discuss the potential impact of this condition on the plantar loading patterns.

Seventy female participants between ages of 18 and 30 were included in this cross-sectional survey. The Beighton-Horan Joint Mobility Index scores were assessed and participants divided into 3 categories: no hypermobility (NH) group, scores 0 to 2; moderate hypermobility (MH) group, scores 3 to 4; distinct hypermobility (DH) group, scores 5 to 9. Pedobarographic analysis was performed both in static and walking conditions. Dynamic foot loading examined in 10 anatomic zones. Contact areas of forefoot, midfoot, and rearfoot were recorded.

In the dynamic pedobarographic analysis, individuals with distinct joint hypermobility displayed higher peak pressure and maximum force values under the hallux, compared with other groups (P < .05). The maximum force value of the second metatarsal was higher in the DH group than in the MH group (P < .05).

Our study results suggest that plantar loading pattern differs with increasing degrees of the hypermobility score.

Differences in plantar loading parameters in people with severe joint mobility scores may be useful in interpreting the foot pathologies of these individuals.

Retrograde intramedullary fibular nail fixation is being utilized with increasing frequency, particularly in patients at higher risk of wound complications. The purpose of this anatomic study was to assess the relative risk to nearby anatomic structures when implanting a contemporary retrograde locked intramedullary fibular nail.

Ten human cadaveric lower extremities were instrumented with a fibular nail. The cadavers were dissected. The shortest distance, in millimeters (mm), between the site of procedural steps and nearby named structures of interest (ie, sural nerve, superficial peroneal nerve, and the peroneal tendons) was measured and recorded. Levels of risk were assigned based on observed distances as high (0 to 5 mm), moderate (5.1-10 mm), and low (greater than 10 mm).

The peroneus brevis (PB) tendon was found to be less than 5.0 mm from the distal skin incision in all specimens. When reaming and inserting the nail through the distal fibula aperture, the PB was less than 5.0 mm in 6 specimens. The peroneus longus tendon was at moderate to high risk when inserting both the proximal and distal syndesmotic screws in 9 specimens. The superficial peroneal nerve was at high risk when inserting an anterior to posterior distal locking screw in 7 specimens. The sural nerve was at low risk for all procedural steps. No structures were violated or damaged during any portion of the fibular nail instrumentation.

The peroneal tendons and superficial peroneal nerve were at the highest risk; however, no structures were injured during instrumentation.

The current findings indicate that strict adherence to sound percutaneous technique is needed in order to minimize iatrogenic damage to neighboring structures when performing retrograde locked intramedullary fibular nail insertion. This includes making skin-only incisions, blunt dissection down to bone, and maintaining close approximation between tissue protection sleeves and bone at all times.