Short-term radiographic analysis of operative correction of adult acquired flatfoot deformity

Comparison of different surgical treatments for stage II progressive collapsing foot deformity: a finite element analysis

BACKGROUND

This study analyzed the advantages and disadvantages of different procedures for stage IIA progressive collapsing foot deformity (PCFD) through three-dimensional finite element models.

METHODS

A previous validated stage IIA PCFD FEA model was established consisting of 16 bones, 56 ligaments, 5 muscles and soft tissues. The ligament properties of the spring, deltoid, short plantar and long plantar ligaments, and plantar fascia were attenuated according to a previous publication. Medial column fusion (MCF), medializing calcaneal osteotomy (MCO), lateral column lengthening (LCL), and subtalar joint arthroereisis (SJA) operations were simulated in this model. The indexes of plantar stress distribution, maximum von Mises of the medial and lateral columns, strain of the medial ligaments and plantar fascia that supported the medial longitudinal arch, arch height, talo-first metatarsal angle, calcaneus pitch angle, and talonavicular coverage angle were all compared before and after simulated single-foot weight loading.

RESULTS

The maximum plantar stress of PCFD decreased with MCO and SJA but increased with MCF and LCL. MCF and LCL failed to significantly reduce the stress on the medial column fragments, thereby increasing their stress. Both MCO and SJA relieved medial plantar stress. MCF had no significant effect on stress relief of the medial ligament. MCO, LCL, and SJA were all shown to reduce the pressure on the medial plantar ligament, with LCL having the most obvious effect. All four procedures corrected the arch deformity; however, MCF was not as effective as the other methods. SJA is the best method for restoring arch height and correcting arch deformities. For stage IIA PCFD, isolated MCF failed to reduce pressure on the medial column; however, isolated MCO significantly reduced the pressure on the medial plantar and ligamentous soft tissues while restoring the foot's arch and correcting the hindfoot valgus.

CONCLUSION

SJA with type II sinus tarsi implant effectively transferred pressure from the medial plantar tract to the lateral side and restored the arch. Isolated LCL was not found suitable for stage IIA PCFD.

Medium- to Long-term Results of Nonanatomic Spring Ligament Reconstruction Using an Allograft Tendon in Progressive Collapsing Foot Deformity With Severe Abduction Deformity

BACKGROUND

Spring ligament reconstruction (SLR) has been suggested as an adjunct to other reconstructive procedures to potentially avoid talonavicular joint fusion in progressive collapsing foot deformity (PCFD) with severe abduction deformity. Most clinical reports present short-term follow-up data and a small number of patients. The purpose of this study was to examine the medium- to long-term outcomes of an SLR using allograft tendon augmentation as part of PCFD surgical reconstruction. This study to our knowledge represents the largest number of patients and the longest follow-up to date.

METHODS

This study retrospectively reviewed 26 patients (27 feet, mean age of 61.4 years) who underwent SLR with allograft tendon as part of PCFD reconstruction. The mean follow-up of the cohort was 8 years (range, 5-13.4). Radiographic evaluation consisted of 5 parameters including talonavicular coverage angle (TNC), with the maintenance of correction being evaluated by comparing parameters from the early postoperative period (mean: 11.6 months, range, 8-17) to final follow-up. Foot and Ankle Outcome Score (FAOS) and patient satisfaction questionnaires were collected at final follow-up. Conversion to talonavicular or subtalar fusion was considered as a failure.

RESULTS

Final radiographs demonstrated successful abduction correction, with the mean TNC improving from 43.7 degrees preoperatively to 14.1 degrees postoperatively (P < .0001). All other radiographic parameters improved significantly and exhibited maintenance of the correction. All FAOS subscales showed significant improvement. Responses to the satisfaction questionnaire were received from all except 1 patient, of whom 88.5% (23/26) were satisfied with the results, 96.2% (25/26) would undergo the surgery again, and 88.5% (23/26) would recommend the surgery. Eight feet (29.6%) required painful hardware removal and 1 (3.7%) developed nonunion of the lateral column lengthening osteotomy. No patient required conversion to talonavicular or subtalar fusion.

CONCLUSION

This study demonstrates favorable medium- to long-term outcomes following PCFD reconstruction including an SLR with allograft tendon augmentation.

LEVEL OF EVIDENCE

Level IV, case series.

Subtalar Fusion for Correction of Forefoot Abduction in Stage II Adult-Acquired Flatfoot Deformity

BACKGROUND

Correction of talonavicular uncoverage (TNU) in adult-acquired flatfoot deformities (AAFD) can be a challenge. Lateral column lengthening (LCL) traditionally is utilized to address this. The primary study objective is examining stage II AAFD patients and determining if correction can be achieved with subtalar fusion (STF) comparable to LCL.

METHODS

Following institutional review board approval, retrospective chart review performed identifying patients meeting criteria for stage IIB AAFD who underwent either STF with concomitant flatfoot procedures (but not LCL) to correct TNU, or who underwent LCL as part of their flatfoot reconstruction. Patients indicated for STF had one or more of the following: higher body mass index (BMI), were older, had greater deformity, lateral impingement pain, intraoperative spring ligament hyperlaxity. Patients without 1-year follow-up or compete records were excluded. All other patients were included. A total of 27 isolated STFs identified, along with 143 who underwent LCL. Pre-/postoperative radiographic parameters obtained as well as PROMIS (Patient-Reported Outcomes Measurement Information System) and FAOS (Foot and Ankle Outcome Score) scores. Radiographic and patient reported outcomes both preoperatively and at 1-year follow-up evaluated for both groups.

RESULTS

STF patients were older (P < .05), with higher BMIs (P < .004). STF had significantly worse TNU (P < .001) than LCL patients, and average change in STF TNU was larger than LCL change postoperatively (P = .006), after adjusting for age, BMI, gender. PROMIS STF improvement reached statistical significance in Physical Function (P 0.011), for FAOS Pain (P 0.025) and Function (P = 0.04).

CONCLUSIONS

STF can be used in appropriately indicated patients to correct flatfoot deformity without compromising radiographic or clinical, correcting not only hindfoot valgus, but also talonavicular uncoverage (TNU) and corresponding medial arch collapse.

LEVELS OF EVIDENCE

Level III: Retrospective chart review comparison study (case control).

Augmented Spring Ligament Repair in Pes Planovalgus Reconstruction

Patients with pes planovalgus deformity often have coexisting spring ligament pathology. A primary repair of the ligament may fail during weightbearing due to chronic degeneration of the ligamentous tissue. Augmentation with a suture tape has been suggested to strengthen the repair. Limited data exist regarding flatfoot reconstruction with augmented spring ligament repair using a suture tape. This is a review of 57 consecutive patients who had flatfoot reconstruction with concomitant spring ligament augmented repair between July 2014 and August 2017. Weightbearing radiographic parameters were obtained preoperatively and compared to radiographs at an average time of 62 ± 46.5 (range 20-220) weeks postoperative. Significant improvements were seen in the radiographic parameters evaluated. Five patients had subsequent operations including one deep infection, 2 hardware removals remote to the spring ligament augmentation, 1 ankle arthrodesis, and 1 triple arthrodesis. Concomitant spring ligament repair augmented with a suture tape was a safe procedure that contributed to radiographic correction in a consecutive series of 57 patients undergoing flatfoot deformity correction.

A Retrospective Radiographic Evaluation of a Modified Method of Lateral Column Lengthening

Background: Lateral column lengthening (LCL) is a commonly performed procedure for patients with stage II adult-acquired flatfoot deformity (AAFD) to correct forefoot abduction. This procedure is frequently completed concomitantly with both soft-tissue and bony procedures, including a medial slide calcaneal osteotomy to further reduce hindfoot valgus. The purpose of this study is to investigate and identify the radiographic outcomes of a modified step-cut LCL utilized as an alternative approach for correction of stage II AAFD. Methods: A retrospective radiographic review was performed on 15 feet in 14 patients who underwent correction of stage II AAFD using a step-cut LCL between August 2009 and January 2012. Two independent examiners utilizing 6 radiographic parameters evaluated preoperative and postoperative weight-bearing radiographs of the foot. Results: At a mean follow-up of 13.4 (range 12-16) weeks, weight-bearing radiographs demonstrated a significant median decrease in the lateral talometatarsal angle of 14.4° (P < .001), lateral talocalcaneal angle of 7° (P < .001), anteroposterior talometatarsal angle of 14.5° (P < .001), anteroposterior talocalcaneal angle of 5.5° (P < .001), and talonavicular coverage angle of 26.5° (P < .001). Additionally, a significant median increase in calcaneal pitch of 8.5° (P < .001) was noted. Conclusion: This study demonstrates statistically significant improvement of radiographic outcomes with use of a modified step-cut LCL as an alternative approach for correction of stage II AAFD.Levels of Evidence: Level IV: Retrospective case series.

Medial displacement calcaneal osteotomy versus lateral column lengthening to treat stage II tibialis posterior tendon dysfunction, a prospective randomized controlled study

PURPOSE

Adult-acquired flatfoot deformity (AAFD) requires optimum planning that often requires several procedures for deformity correction. The objective of this study was to detect the difference between MDCO versus LCL in the management of AAFD with stage II tibialis posterior tendon dysfunction regarding functional, radiographic outcomes, efficacy in correction maintenance, and the incidence of complications.

PATIENT AND METHODS

42 Patients (21 males and 21 females) with a mean age of 49.6 years (range 43-55), 22 patients had MDCO while 20 had LCL. Strayer procedure, spring ligament plication, and FDL transfer were done in all patients. Pre- and Postoperative (at 3 and 12 months) clinical assessment was done using AOFAS and FFI questionnaire. Six radiographic parameters were analyzed, Talo-navicular coverage and Talo-calcaneal angle in the AP view, Talo- first metatarsus angle, Talo-calcaneal angle and calcaneal inclination angle in lateral view and tibio-calcaneal angle in the axial view, complications were reported.

RESULTS

At 12 months, significant improvement in AOFAS and FFI scores from preoperative values with no significant difference between both groups. Postoperative significant improvements in all radiographic measurements in both groups were maintained at 12 months. However, the calcaneal pitch angle and the TNCA were better in the LCL at 12 months than MDCO, 17̊±2.8 versus 13.95̊±2.2 (p=0.001) and 13.70̊±2.2 versus 19.05̊±3.2 (p<0.001) respectively. 11 patients (26.2%) had metal removal, seven (16.6%) in the MDCO, and four (9.6%) in the LCL. Three (7.1%) in the LCL group had subtalar arthritis, only one required subtalar fusion.

CONCLUSION

LCL produced a greater change in the realignment of AAFD, maintained more of their initial correction, and were associated with a lower incidence of additional surgery than MDCO, however, a higher incidence of degenerative change in the hindfoot was observed with LCL.

Natural History of 321 Flatfoot Reconstructions in Adult Acquired Flatfoot Deformity Over a 14-Year Period

The purpose of this study was to report the natural history, demographics, and mechanisms of requirement for additional surgery in patients undergoing flatfoot reconstruction for adult acquired flatfoot. A total of 321 consecutive patients undergoing flatfoot reconstruction over a 14-year period were included (2002-2016). All procedures were performed by a senior orthopaedic foot and ankle surgeon at our institution. Demographic data, operative reports, clinic notes, and radiographs were available for review. Statistical analysis included calculation of relative risk (RR) ratios. The majority of patients were female (83.2%,) and most patients were overweight with a body mass index greater than 25 kg/m² (56.4%). Patient comorbidities included diabetes (13.7%) and rheumatoid arthritis (3.7%). Additional surgery was required for 54 patients (16.8%). The most common reasons for additional surgery were the following: painful calcaneal hardware (57.4%), conversion to triple arthrodesis (16.7%), and wound healing complications (9.1%). An increased risk of need for additional surgery was associated with female gender (RR = 3.4; P = .0005), smoking status (RR = 1.9; P = .0081), and age (<60 years of age; RR = 1.8; P = .042). Although retrospective, the results provide insight into the natural history of this procedure. Clinicians may use these data to appropriately counsel patients who are at increased risk of requirement for additional surgery, such as smokers, women, and patients <60 years old, regarding treatment options.Levels of Evidence: Level IV.

Weight-bearing radiographs and cone-beam computed tomography examinations in adult acquired flatfoot deformity

BACKGROUND

Optimal characterization of Adult acquired flatfoot deformity (AAFD) on two-dimensional radiograph can be challenging. Weightbearing Cone Beam CT (CBCT) may improve characterization of the three-dimensional (3D) structural details of such dynamic deformity. We compared and validated AAFD measurements between weightbearing radiograph and weightbearing CBCT images.

METHODS

20 patients (20 feet, right/left: 15/5, male/female: 12/8, mean age: 52.2) with clinical diagnosis of flexible AAFD were prospectively recruited and underwent weightbearing dorsoplantar (DP) and lateral radiograph as well as weightbearing CBCT. Two foot and ankle surgeons performed AAFD measurements at parasagittal and axial planes (lateral and DP radiographs, respectively). Intra- and Inter-observer reliabilities were calculated by Intraclass correlation (ICC) and Cohen's kappa. Mean values of weightbearing radiograph and weightbearing CBCT measurements were also compared.

RESULTS

Except for medial-cuneiform-first-metatarsal-angle, adequate intra-observer reliability (range:0.61-0.96) was observed for weightbearing radiographic measurements. Moderate to very good interobserver reliability between weightbearing radiograph and weightbearing CBCT measurements were observed for the following measurements: Naviculocuneiform-angle (ICC:0.47), Medial-cuneiform-first-metatarsal-gapping (ICC:0.58), cuboid-to-floor-distance (ICC:0.68), calcaneal-inclination-angle(ICC:0.7), axial Talonavicular-coverage-angle(ICC:0.56), axial Talus-first-metatarsal-angle(ICC:0.62). Comparing weightbearing radiograph and weightbearing CBCT images, statistically significant differences in the mean values of parasagittal talus-first-metatarsal-angle, medial-cuneiform-first-metatarsal-angle, medial-cuneiform-to-floor-distance and navicular-to-floor-distance was observed (P < 0.05).

CONCLUSION

Moderate to very good correlation was observed between certain weightbearing radiograph and weightbearing CBCT measurements, however, significant difference was observed between a number of AAFD measurements, which suggest that 2D radiographic evaluation could potentially underestimate the severity of AAFD, when compared to 3D weightbearing CT assessment.

American College of Foot and Ankle Surgeons Clinical Consensus Statement: Appropriate Clinical Management of Adult-Acquired Flatfoot Deformity

This clinical consensus statement of the American College of Foot and Ankle Surgeons focuses on the highly debated subject of the management of adult flatfoot (AAFD). In developing this statement, the AAFD consensus statement panel attempted to address the most relevant issues facing the foot and ankle surgeon today, using the best evidence-based literature available. The panel created and researched 16 statements and generated opinions on the appropriateness of the statements. The results of the research on this topic and the opinions of the panel are presented here.

Consensus for the Indication of Lateral Column Lengthening in the Treatment of Progressive Collapsing Foot Deformity

RECOMMENDATION

Progressive collapsing foot deformity (PCFD) is a complex 3D deformity with varying degrees of hindfoot valgus, forefoot abduction, and midfoot supination. Although a medial displacement calcaneal osteotomy can correct heel valgus, it has far less ability to correct forefoot abduction. More severe forefoot abduction, most frequently measured preoperatively by assessing talonavicular coverage on an anteroposterior (AP) weightbearing conventional radiographic view of the foot, can be more effectively corrected with a lateral column lengthening procedure than by other osteotomies in the foot. Care must be taken intraoperatively to not overcorrect the deformity by restricting passive eversion of the subtalar joint or causing adduction at the talonavicular joint on simulated AP weightbearing fluoroscopic imaging. Overcorrection can lead to lateral column overload with persistent lateral midfoot pain. The typical amount of lengthening of the lateral column is between 5 and 10 mm.

LEVEL OF EVIDENCE

Level V, consensus, expert opinion.

CONSENSUS STATEMENT ONE

Lateral column lengthening (LCL) procedure is recommended when the amount of talonavicular joint uncoverage is above 40%. The amount of lengthening needed in the lateral column should be judged intraoperatively by the amount of correction of the uncoverage and by adequate residual passive eversion range of motion of the subtalar joint.Delegate vote: agree, 78% (7/9); disagree, 11% (1/9); abstain, 11% (1/9).(Strong consensus).

CONSENSUS STATEMENT TWO

When titrating the amount of correction of abduction deformity intraoperatively, the presence of adduction at the talonavicular joint on simulated weightbearing fluoroscopic imaging is an important sign of hypercorrection and higher risk for lateral column overload.Delegate vote: agree, 100% (9/9); disagree, 0%; abstain, 0%.(Unanimous, strongest consensus).

CONSENSUS STATEMENT THREE

The typical range for performing a lateral column lengthening is between 5 and 10 mm to achieve an adequate amount of talonavicular coverage.Delegate vote: agree, 100% (9/9); disagree, 0%; abstain, 0%.(Unanimous, strongest consensus).

Consensus on Indications for Isolated Subtalar Joint Fusion and Naviculocuneiform Fusions for Progressive Collapsing Foot Deformity

RECOMMENDATION

Peritalar subluxation represents an important hindfoot component of progressive collapsing foot deformity, which can be associated with a breakdown of the medial longitudinal arch. It results in a complex 3-dimensional deformity with varying degrees of hindfoot valgus, forefoot abduction, and pronation. Loss of peritalar stability allows the talus to rotate and translate on the calcaneal and navicular bone surfaces, typically moving medially and anteriorly, which may result in sinus tarsi and subfibular impingement. The onset of degenerative disease can manifest with stiffening of the subtalar (ST) joint and subsequent fixed and possibly arthritic deformity. While ST joint fusion may permit repositioning and stabilization of the talus on top of the calcaneus, it may not fully correct forefoot abduction and it does not correct forefoot varus. Such varus may be addressed by a talonavicular (TN) fusion or a plantar flexion osteotomy of the first ray, but, if too pronounced, it may be more effectively corrected with a naviculocuneiform (NC) fusion. The NC joint has a curvature in the sagittal plane. Thus, preserving the shape of the joint is the key to permitting plantarflexion correction by rotating the midfoot along the debrided surfaces and to fix it. Intraoperatively, care must be also taken to not overcorrect the talocalcaneal angle in the horizontal plane during the ST fusion (eg, to exceed the external rotation of the talus and inadvertently put the midfoot in a supinated position). Such overcorrection can lead to lateral column overload with persistent lateral midfoot pain and discomfort. A contraindication for an isolated ST fusion may be a rupture of posterior tibial tendon because of the resultant loss of the internal rotation force at the TN joint. In these cases, a flexor digitorum longus tendon transfer is added to the procedure.

LEVEL OF EVIDENCE

Level V, consensus, expert opinion.

Tarsometatarsal bone remodelling after subtalar arthroereisis

PURPOSE

Subtalar arthroereisis has been described for the treatment of flexible juvenile flatfoot. However, the mechanism responsible for deformity correction has not yet been investigated adequately. The aim of this study was to document the effect of subtalar arthroereisis on the tarsometatarsal bone morphology.

METHODS

We retrospectively reviewed the clinical and radiological data of 26 patients (45 feet) with juvenile flexible flatfoot deformity treated by subtalar arthroereisis at our department between 2000 and 2018. Radiological evaluation included angular measurements of tarsometatarsal bone morphology as well as hindfoot and midfoot alignment. Mean radiographic follow-up was 19.4 months (sd 8.8; 12 to 41).

RESULTS

A significant change of angular measurements of tarsometatarsal bone morphology was found after subtalar arthroereisis (p < 0.001). While there was an increase of the distal medial cuneiform angle (DMCA) and the medial cuneo-first metatarsal angle on the anteroposterior view, a decrease of the naviculo-medial cuneiform angle and the medial cuneo-first metatarsal angle was seen on the lateral view. Furthermore, we found significant improvements of all hindfoot and midfoot alignment parameters except the lateral tibio-calcaneal angle and the calcaneal pitch angle (p < 0.001).

CONCLUSION

Our data support the theory of tarsometatarsal bone remodelling, which may contribute to the effect of subtalar arthroereisis for the treatment of flexible juvenile flatfoot.

LEVEL OF EVIDENCE

IV.

Effectiveness of subtalar arthroereisis with endorthesis for pediatric flexible flat foot: a retrospective cross-sectional study with final follow up at skeletal maturity

BACKGROUND

Pediatric flexible flatfoot is sometimes asymptomatic but it can rarely cause physical impairment, pain, and difficulty walking. We evaluated the radiographic effectiveness of intervention of subtalar arthroereisis with endorthesis for pediatric flexible flatfoot with final follow-up at skeletal maturity.

METHODS

This is a retrospective cross-sectional study. 56 consecutive patients (112 feet) who underwent surgical treatment with subtalar arthroereisis for pediatric flexible flatfoot (mean age at final follow-up 15.5±1.2 years, 39.3% female) were enrolled. All the radiographic studies were performed in the hospital. Radiographs (standard weight-bearing radiographs of the foot with anteroposterior and lateral view) were used to measure lateral talocalcaneal angle (LTC), calcaneal pitch angle (CP), Meary's angle (MA), anteroposterior talonavicular angle (APTN), talonavicular uncoverage percent (TNU). Minimum follow-up was 18 months. Measures were assessed pre-operatively and at the final follow-up. Clinical and functional parameters were assessed at the final follow-up.

RESULTS

Children who underwent surgical treatment with subtalar arthroereisis for pediatric flexible flatfoot exhibited a statistically significant improvement in all radiographic measurement parameters at the last follow-up at skeletal maturity (all, p<0.004). Mean follow-up was 40.1±23.6months. Clinical parameters were not correlated with the foot radiographic parameters at follow up period.

CONCLUSIONS

Our results suggest that endorthesis in pediatric flexible flatfoot was effective for improving radiographic parameters at skeletal maturity. The amount of the morphologic correction at the end of the skeletal growth should be expected mainly for lateral tarso-metatarsal alignment and talo-navicular congruency (MA, APTN, TNU).

LEVEL OF EVIDENCE

Level III, retrospective study.

Outcomes of the Extended Z-Cut Osteotomy for Correction of Adult Acquired Flatfoot Deformity

BACKGROUND

Medial displacement calcaneus tuberosity osteotomy and anterior process lengthening calcaneus osteotomy are traditional single-plane osteotomy techniques used in adult acquired flatfoot deformity reconstruction. More recently, 3-plane step-cut osteotomies were described for each of these and shown to offer improved rotational stability via the horizontal limb. However, a major technical challenge is achieving a sufficiently long horizontal limb to correct deformity through lengthening without losing bony apposition. Combining the anterior process and tuberosity step-cuts using an elongated horizontal limb alleviates this technical challenge, creates a very large surface area for bony healing, and utilizes a single incision. We hypothesized that the Z-cut osteotomy would achieve clinical and radiographic flatfoot deformity correction with a high union rate.

METHODS

This was an institutional review board-approved retrospective study of 16 patients who underwent Z-cut osteotomy for the treatment of moderate to severe symptomatic adult acquired flatfoot deformity, stage IIA/B. The mean radiographic follow-up was 8.8 months, while the mean clinical follow-up was 2.36 years. Radiographic correction was assessed via weightbearing radiographs taken preoperatively and at a mean of 26 ± 2 weeks postoperatively. Measurements included Meary's angle (talo-first metatarsal angle), talonavicular (TN) joint uncoverage percentage, TN incongruency angle, medial cuneiform to fifth metatarsal height, and calcaneal pitch. Union rates and clinical outcomes via the Foot Function Index (FFI) score were assessed preoperatively and at a mean of 29 months following surgery. Paired t test was used to compare both clinical and radiographic outcomes with statistical significance set at P < .05.

RESULTS

Fifteen of 16 patients returned an FFI questionnaire with a mean improvement of 52.1 to 10.3 (P = .002). The calcaneal pitch improved from 12.7 to 15.2 degrees (P = .002), the medial cuneiform-fifth metatarsal distance improved from 12.8 to 18.5 mm (P = .002), the TN coverage angle improved from 21.3 to 9.1 degrees (P < .001), the TN uncoverage percentage improved from 32.9% to 20.3% (P < .001), and the TN incongruency angle improved from 41.4 to 19.9 degrees (P < .001). Deformity correction was well maintained in 13 of 16 patients at final follow-up. The union rate of the osteotomy was 100%. Three patients had symptomatic hardware initially; 1 patient required removal of hardware. One patient developed a superficial infection that cleared. Another patient developed peroneal tendonitis, which resolved with corticosteroid injection.

CONCLUSION

The Z-cut osteotomy is a novel, technically simplified, single-incision, single-osteotomy alternative to the previously described double calcaneus osteotomy techniques for reconstructing flexible moderate to severe adult acquired flatfoot deformity that offers comparable short-term clinical and radiographic outcomes with acceptably low complications.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Influence of investigator experience on reliability of adult acquired flatfoot deformity measurements using weightbearing computed tomography

BACKGROUND

Our purpose was to assess the reliability of measurements of adult-acquired flatfoot deformity (AAFD) taken by investigators of different levels of clinical experience using weightbearing computed tomography (WBCT).

METHODS

Nineteen AAFD patients underwent WBCT. Three investigators with different levels of clinical experience made AAFD measurements in axial, coronal, and sagittal planes. Intra- and interobserver reliability were assessed. Mean values for each measurement were compared between investigators.

RESULTS

After a training protocol, substantial to perfect intra- and interobserver reliability was observed for most measures, regardless of the investigator's experience level. Significant differences between investigators were observed in 2 of 21 measured parameters: medial cuneiform-first metatarsal angle (P=0.003) and navicular-medial cuneiform angle (P=0.001).

CONCLUSIONS

AAFD radiographic measurements can be performed reliably by investigators with different levels of clinical experience using WBCT.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Surgical procedures for treatment of adult acquired flatfoot deformity: a network meta-analysis

Background

Adult acquired flatfoot deformity (AAFD) represents a spectrum of deformities affecting the foot and the ankle. The optimal management of AAFD remains controversial. We evaluated the efficacy of surgical treatments of AAFD using both direct and indirect evidences.

Methods

We searched PubMed, EmBase, and the Cochrane Library to identify eligible studies conducted through November 2018. To compare different surgical strategies, we performed a network meta-analysis. A traditional meta-analysis using a random-effects model was used to evaluate the pooled outcome.

Results

A total of 21 studies including 498 patients were collected and analyzed. Network meta-analysis results based on lateral angle talocalcaneal-calcaneal pitch (LAT-CP) indicated that medial displacement calcaneal osteotomy (MDCO) has the highest probability to be the best course of AAFD treatment. However, analyses based on anteroposterior talo-first metatarsal (AP-TMT1) and lateral angle talocalcaneal talo-first metatarsal (LAT-TMT1) suggested that lateral column lengthening (LCL) was the best treatment, while those based on lateral angle talocalcaneal-arch height, anteroposterior talocalcaneal (AP-TC), lateral angle talocalcaneal-talocalcaneal (LAT-TC), anteroposterior-talonavicular coverage (AP-TNC), talonavicular coverage (TNC), and the American Orthopedic Foot and Ankle Society (AOFAS) indicated triple arthrodesis (TAO) as the best treatment. Moreover, double arthrodesis (DAO) provided the best treatment effect on the function score. Furthermore, according to traditional meta-analysis, the summary of standardized mean differences (SMD) indicated that the surgical interventions are associated with significant improvements in LAT-CP (SMD − 1.78), LAT-arch height (SMD − 4.95), AOFAS (SMD − 5.24), AP-TMT1 (SMD 2.45), LAT-TMT1 (SMD 1.97), AP-TC (SMD 3.05), LAT-TC (SMD 2.20), AP-TNC (SMD 2.07), TNC (SMD 1.70), and function score (SMD 0.95).

Conclusions

Our findings indicated that MDCO, LCL, TAO, or DAO might be the best surgical approaches for AAFD treatment. Furthermore, patients who received surgical interventions had significant improvements in symptoms and function.

Electronic supplementary material

The online version of this article (10.1186/s13018-019-1094-0) contains supplementary material, which is available to authorized users.

Adult-Acquired Flatfoot Deformity

Adult-acquired flatfoot deformity (AAFD) comprises a wide spectrum of ligament and tendon failure that may result in significant deformity and disability. It is often associated with posterior tibial tendon deficiency (PTTD), which has been linked to multiple demographic factors, medical comorbidities, and genetic processes. AAFD is classified using stages I through IV. Nonoperative treatment modalities should always be attempted first and often provide resolution in stages I and II. Stage II, consisting of a wide range of flexible deformities, is typically treated operatively with a combination of soft tissue procedures and osteotomies. Stage III, which is characterized by a rigid flatfoot, typically warrants triple arthrodesis. Stage IV, where the flatfoot deformity involves the ankle joint, is treated with ankle arthrodesis or ankle arthroplasty with or without deltoid ligament reconstruction along with procedures to restore alignment of the foot. There is limited evidence as to the optimal procedure; thus, the surgical indications and techniques continue to be researched.

The arthroereisis procedure in adult flexible flatfoot grade IIA due to insufficiency of posterior tibial tendon

BACKGROUND

To report on the functional, biomechanical, and radiographic results of patients who had undergone arthroereisis plus tensioning of the posterior tibial tendon for flexible flatfoot. The hypothesis is that arthroereisis associated to a tensioning of the posterior tibial tendon give a good correction with great satisfaction in patients with flexible flatfoot in grade IIA.

METHODS

We evaluated 29 patients (31 feet), mean age of 46.4 years, who had been surgically treated for adult flatfoot grade IIA according to Myerson. Mean follow-up was 34.15 months. For clinical evaluation, the AOFAS hindfoot and VAS-FA scores were used.

RESULTS

Postoperative results showed significant increases in both AOFAS and VAS-FA scores: 54.2-81.9 and 61.5-83.2 points, respectively. For the X-ray parameters, we observed a significant variation in the talo-first metatarsal angle, from 13.8° in pre-op to 7.4° in post-op. In lateral view, Djian Annonier angle was improved from 146.6° to 134.1°. The Meary's angle, compared to an average of 8.8° in pre-operative stage improved to 4.3° in the post-operative stage. Postoperative satisfaction was excellent-good according to 23 patients (79.4%). Pain in the tarsal sinus was reported in 5 out of 31 feet (16.1%) for the first three months after surgery.

CONCLUSIONS

Arthroereisis and tensioning of the posterior tibial tendon provided good functional outcomes for patients under 60 years of age having stage IIA flexible flatfoot without arthritic manifestations.

Minimal Incision/Minimally Invasive Medializing Displacement Calcaneal Osteotomy

Minimally invasive techniques are readily applicable to calcaneal osteotomies and have the potential to accomplish hindfoot correction equivalent to open procedures with less morbidity and pain. Use of a guidance jig makes the procedure more predictable. While most anatomic features of the procedure are the same as those with open techniques, special care must be taken to avoid neurovascular injury because there is no open exposure. Anatomic guidelines have been established for appropriately localizing the osteotomy.

LEVEL OF EVIDENCE

Level V, expert opinion.

Flexible Adult Acquired Flatfoot Deformity: Comparison Between Weight-Bearing and Non-Weight-Bearing Measurements Using Cone-Beam Computed Tomography

BACKGROUND

The 3-dimensional nature of adult acquired flatfoot deformity can be challenging to characterize using radiographs. We tested the hypothesis that measurements on weight-bearing (WB) cone-beam computed tomography (CT) images were more useful for demonstrating the severity of the deformity than non-weight-bearing (NWB) measurements.

METHODS

We prospectively enrolled 12 men and 8 women (mean age, 52 years; range, 20 to 88 years) with flexible adult acquired flatfoot deformity. The subjects underwent cone-beam CT while standing (WB) and seated (NWB), and images were assessed in the sagittal, coronal, and axial planes by 3 independent observers who performed multiple measurements. Intraobserver and interobserver reliabilities were assessed with the Pearson or Spearman correlation and the intraclass correlation coefficient (ICC), respectively. Measurements were compared using paired Student t tests or Wilcoxon rank-sum tests. P < 0.05 was considered significant.

RESULTS

We found that overall the measurements had substantial intraobserver and interobserver reliability on both the NWB images (mean ICC, 0.80; range, 0.49 to 0.99) and the WB images (mean ICC, 0.81; range, 0.39 to 0.99). Eighteen of 19 measurements differed between WB and NWB cone-beam CT images, with more pronounced deformities on the WB images. The most reliable measurements, based on intraobserver and interobserver reliabilities and the difference between WB and NWB images, were the medial cuneiform-to-floor distance, which averaged 29 mm (95% confidence interval [CI] = 28 to 31 mm) on the NWB images and 18 mm (95% CI = 17 to 19 mm) on the WB images, and the forefoot arch angle (mean, 13° [95% CI = 12° to 15°] and 3.0° [95% CI = 1.4° to 4.6°], respectively) in the coronal view and the cuboid-to-floor distance (mean, 22 mm [95% CI = 21 to 23 mm] and 17 mm [95% CI = 16 to 18 mm], respectively) and the navicular-to-floor distance (mean, 38 mm [95% CI = 36 to 40 mm] and 23 mm [95% CI = 22 to 25 mm], respectively) in the sagittal view.

CONCLUSIONS

Measurements analogous to traditional radiographic parameters of adult acquired flatfoot deformity are obtainable using high-resolution cone-beam CT. Compared with NWB images, WB images better demonstrated the severity of osseous derangement in patients with flexible adult acquired flatfoot deformity.

LEVEL OF EVIDENCE

Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Overcorrected Flatfoot Reconstruction

The overcorrected flatfoot reconstruction is a less common but often difficult sequelae of surgical treatment of the adult acquired flatfoot deformity. Understanding the patient's symptoms and how they correlate to the procedures performed during the index surgery are paramount to determining the appropriate course of treatment. Patients' symptoms may resemble those seen in the cavovarus foot condition, often secondary to overlengthening of the lateral column or excessive displacement of the calcaneal tuberosity. Osteotomies of the calcaneus, midfoot, and often the first metatarsal may be sufficient to revise the overcorrection. However, hindfoot and/or midfoot arthrodesis may be required in more severe or rigid cases.

Evans Osteotomy Complications

In 1975, Evans published an article describing the surgical management of the "calcaneo-valgus deformity," pointing out that the deformity was due to relative shortening of the lateral column of the foot. Correction involved "equalizing" both columns by performing an osteotomy in the neck of the calcaneus 1.5 cm from the calcaneocuboid joint, where a trapezoidal wedge of tricortical bone was placed. Although it was considered a success, there were complications, including sural nerve injury, surgical wound dehiscence, undercorrection, and graft subsidence. The osteotomy grew in popularity. Indications extended to other forms of flatfoot with a low incidence of complications.

Contribution of Lateral Column Lengthening to Correction of Forefoot Abduction in Stage IIb Adult Acquired Flatfoot Deformity Reconstruction

BACKGROUND

Correction of forefoot abduction in stage IIb adult acquired flatfoot likely depends on the amount of lateral column lengthening (LCL) performed, although this represents only one aspect of a successful reconstruction. The purpose of this study was to evaluate the correlation between common reconstructive variables and the observed change in forefoot abduction.

METHODS

Forty-one patients who underwent flatfoot reconstruction involving an Evans-type LCL were assessed retrospectively. Preoperative and postoperative anteroposterior (AP) radiographs of the foot at a minimum of 40 weeks (mean, 2 years) after surgery were reviewed to determine correction in forefoot abduction as measured by talonavicular coverage (TNC) angle, talonavicular uncoverage percent, talus-first metatarsal (T-1MT) angle, and lateral incongruency angle. Fourteen demographic and intraoperative variables were evaluated for association with change in forefoot abduction including age, gender, height, weight, body mass index, as well as the amount of LCL and medializing calcaneal osteotomy performed, LCL graft type, Cotton osteotomy, first tarsometatarsal fusion, flexor digitorum longus transfer, spring ligament repair, gastrocnemius recession and any one of the modified McBride/Akin/Silver procedures.

RESULTS

Two variables significantly affected the change in lateral incongruency angle. These were weight (P = .04) and the amount of LCL performed (P < .001). No variables were associated with the change in TNC angle, talonavicular uncoverage percent, or T-1MT angle. Multivariate regression analysis revealed that LCL was the only significant predictor of the change in lateral incongruency angle. The final regression model for LCL showed a good fit (R2 = 0.70, P < .001). Each millimeter of LCL corresponded to a 6.8-degree change in lateral incongruency angle.

CONCLUSION

Correction of forefoot abduction in flatfoot reconstruction was primarily determined by the LCL procedure and could be modeled linearly. We believe that the lateral incongruency angle can serve as a valuable preoperative measurement to help surgeons titrate the proper amount of correction performed intraoperatively.

Stage I and II Posterior Tibial Tendon Dysfunction: Return to Running?

Posterior tibial tendon dysfunction can be a difficult entity to treat in the athletic population. Understanding the deformity components allows the physician to maximize nonoperative intervention with orthotics and physical therapy. Not all patients improve with nonoperative treatment, and surgical intervention can be successful in minimizing symptoms. Although return to full athletic activity is not universally possible, an active lifestyle is possible for many after surgical reconstruction.

Radiographic Outcomes Following Lateral Column Lengthening With a Porous Titanium Wedge

BACKGROUND

Lateral column lengthening (LCL) is commonly utilized in treating stage II posterior tibialis tendon dysfunction. This study aimed to analyze the outcomes of LCL with porous titanium wedges compared to historic controls of iliac crest autograft and allograft. We hypothesized that the use of a porous titanium wedge would have radiographic improvement and union rates similar to those with the use of autograft and allograft in LCL.

METHODS

Between May 2009 and May 2014, 28 feet in 26 patients were treated with LCL using a porous titanium wedge. Of the 26 patients, 9 were males (34.6%). The average age for males was 43 years (range, 17.9-58.7), 48.7 years (range, 21-72.3) for females. Mean follow-up was 14.6 months. Radiographs were examined for correction of the flatfoot deformity and forefoot abduction. All complications were noted.

RESULTS

Radiographically, the patients had a significant deformity correction in the anteroposterior talo-first metatarsal angle, talonavicular coverage angle, lateral talo-first metatarsal angle, and calcaneal pitch. All but 1 patient (96%) had bony incorporation of the porous titanium wedge. The average preoperative visual analog scale pain score was 5; all patients but 3 (12%) had improvements in their pain score, with a mean change of 3.4.

CONCLUSION

LCL with porous titanium had low nonunion rates, improved radiographic correction, and pain relief.

LEVEL OF EVIDENCE

Level IV, case series.

Arterial anatomy of the tibialis posterior tendon

BACKGROUND

Tibialis posterior tendon dysfunction is a common disorder leading to pain, deformity, and disability, although its pathogenesis is unclear. A vascular etiology has been proposed, but there is controversy regarding the existence of a hypovascular region that may render the tendon vulnerable. The purpose of this study was to provide a description of the arterial anatomy supplying the tibialis posterior tendon.

METHODS

Sixty adult cadaveric lower extremities were obtained from a university-affiliated body donation program. Thirty specimens obtained within 72 hours of death were used for microscopic analysis. Thirty specimens were previously frozen and used for macroscopic analysis. The tibialis anterior, tibialis posterior, and peroneal arteries were injected with India Ink and Ward's Blue Latex. The specimens used for macroscopic analysis were debrided with sodium hypochlorite to expose the extratendinous anatomy. For the microscopic analysis, the tendon was cleared using a modified Spälteholz technique to expose the intratendinous vascular anatomy.

RESULTS

Macroscopically, an average of 2.5 ± 0.7 vessels entered the tendon proximal to the navicular insertion. In all, 28/30 (93.3%) specimens had a vessel entering 4.1 ± 0.6 cm proximal to the medial malleolus and 24/30 (80.0%) specimens had a vessel entering 1.7 ± 0.9 cm distal to the medial malleolus. Microscopically, an average of 1.9 ± 0.3 vessels entered each tendon proximal to the navicular insertion. In total, 27/30 (90%) specimens had a vessel entering the tendon 4.8 ± 0.8 cm proximal to the medial malleolus and 30/30 (100%) specimens had a vessel entering the tendon 1.9 ± 0.8 cm distal to the medial malleolus. In all specimens, a hypovascular region was observed, starting 2.2 ± 0.8 cm proximal to the medial malleolus and ending 0.6 ± 0.6 cm proximal to the medial malleolus with an average length of 1.5 ± 1.0 cm. The insertion of the tendon was well vascularized both on microscopic and macroscopic specimens.

CONCLUSION

The tibialis posterior tendon was supplied by 2 vessels entering the tendon approximately 4.5 cm proximal and 2.0 cm distal to the medial malleolus. A retromalleolar hypovascular region was observed.

CLINICAL RELEVANCE

Improved understanding of the vascularity of the tibialis posterior tendon may be helpful in clinical practice and potentially provides a basis for further evaluation of the causative factors of tibialis posterior tendinopathy.

Results of operative correction of grade IIB tibialis posterior tendon dysfunction

BACKGROUND

The prevalence of tibialis posterior tendon dysfunction (PTTD) is estimated to be as high as 3% to 4% in Western populations, and it is one of the most commonly misdiagnosed conditions of the foot and ankle.

METHODS

Clinical and radiological outcomes were assessed in grade IIB PTTD treated with a medializing calcaneal osteotomy, lateral column lengthening, flexor digitorum longus transfer, and tendo-Achilles lengthening. The clinical and radiological findings recorded were the SF-36 score on physical function and mental health, midfoot and hindfoot American Orthopaedic Foot and Ankle Society (AOFAS) clinical scores, the midfoot and visual analog pain scores, as well as the radiological measurements of the hindfoot calcaneal pitch, talo-first metatarsal angle, and medial cuneiform height. The time points of assessment were preoperatively, 6 months postoperatively, and 24 months postoperatively by an examiner different from the operating surgeon.

RESULTS

The SF-36 score on physical function (mean difference of 8.7 and 8.2, respectively), AOFAS midfoot score (mean difference of 29.6 and 15.3, respectively), AOFAS ankle-hindfoot score (mean difference of 23.2 and 14.3, respectively), midfoot visual analog pain score (mean difference of 4.0 and 1.2), and the ankle and hindfoot visual analog score (mean difference of 3.6 and 1.6) all had significant reduction from the preoperative to the 24-month postoperative time point (P < .001). Radiologically, there was also correction of the deformity associated with PTTD. The hindfoot calcaneal pitch was corrected from 8.4 degrees to 18.7 degrees. The talo-first metatarsal angle was corrected from 14.0 degrees to 1.3 degrees, and the medial cuneiform height was corrected from 10.3 mm to 20.4 mm at 24 months postoperatively.

CONCLUSION

Grade IIB PTTD treated with a medializing calcaneal osteotomy, lateral column lengthening, flexor digitorum longus transfer, and tendo-Achilles lengthening demonstrated statistical significant improvement in hindfoot and midfoot AOFAS scores, SF-36 physical function scores, as well as visual analog scores. The complications were minimal. We advocate the combination of these procedures as being successful for the treatment of grade IIB PTTD. Longer term follow-up is needed to determine if these improvements plateau, improve, or deteriorate.

LEVEL OF EVIDENCE

Level IV, retrospective case series.