Displaced Proximal Tibia Fracture After Proximal Tibial Autograft Harvest: A Case Report.

Background: A 60-year-old female underwent proximal tibial autograft harvest for a Cotton osteotomy. Her postoperative course was complicated by psychogenic non-epileptic seizure (PNES) episodes leading to unintentional weightbearing. Knee radiographs at 6 weeks post-procedure demonstrated a displaced proximal tibia fracture through the autograft harvest site. Further clinical review revealed metabolic derangements consistent with secondary hyperparathyroidism. Initial nonoperative treatment led to atrophic varus nonunion requiring definitive treatment with total knee arthroplasty with revision components. Conclusion: This case describes a rare complication of proximal tibial autograft harvest and highlights the importance of preoperative metabolic workup and bone health optimization.Level of Evidence: IV.

A Case Report of Isolated Cervical Ligament Rupture With Hyper-Pronation Injury: Specific MRI Protocol and Surgical Reconstruction.

Background: The aim of this case report is to present a case of chronic cervical ligament tear and instability, which occurred by an unusual work injury with an eversion/hyper-pronation mechanism in contrast to the usual mechanism of inversion. The ligament was reconstructed using an allograft with satisfactory results up to 30 months after surgery. A new magnetic resonance imaging protocol (MRI) was developed to better evaluate the cervical ligament/graft. Conclusion: In diagnosis of foot sprains, a specific ligament injury should always be sought. In this case, physical examination producing tenderness at the location of the cervical ligament and correlating this with an oblique intercolumn stress test that reproduced pain with apprehension and gross instability supported the diagnosis. Retrospectively applying anatomic knowledge to the earlier MRI findings of bone marrow edema at the insertion points of the cervical ligament on the talus and calcaneus was important in confirming the diagnosis. To better evaluate the cervical ligament allograft tendon reconstruction, a novel volumetric MRI sequence was developed which may prove helpful to also diagnose cervical ligament injuries in future cases. Anatomic reconstruction of the cervical ligament provided satisfactory clinical and radiographic results at 30-month follow-up.Level of Evidence: V.

A Case Report of Brodie's Abscess of the Cuboid Treated by Anatomic Antibiotic-Cement Spacer.

Background: A case of chronic osteomyelitis with Brodie's abscess of the cuboid caused by a wooden foreign body penetrating the plantar foot. Total cuboidectomy was carried out with implantation of an anatomically molded antibiotic-impregnated cement spacer with culture-specific postoperative intravenous antibiotics. At six months of follow-up, the patient was completely asymptomatic without evidence of a recurrence of infection. Final radiographs also didn't show spacer migration or surrounding bone erosions. The spacer obviated the need for any foot fusion which preserved foot biomechanics. The patient didn't need to use any braces or insoles. Conclusion: Osteomyelitis should always be on the differential list of lytic lesions of the tarsal bones, especially if there is a history of prior foot trauma. In this case, cuboid excision and placement of an antibiotic-impregnated cement spacer provided sustained relief of symptoms without evidence of recurrence or complications for six months.Level of Evidence: V.

Posterior Ankle Impingement: It's Not Only About the Os Trigonum.

Background: Os trigonum and Stieda process are common etiologies for posterior ankle impingement syndrome (PAIS), and diagnosis is typically made by radiographs, computed tomographic, or magnetic resonance imaging. However, these static tests may not detect associated soft tissue and bony pathologies. Posterior ankle and hindfoot arthroscopy (PAHA) is dynamic, providing at least ×8 magnification with full anatomical visualization. The primary aim of this study was to report the prevalence of associated conditions seen with trigonal impingement treated with PAHA. Methods: In this retrospective comparative study, patients who underwent PAHA for PAIS due to trigonal impingement, from January 2011 to September 2016, were reviewed. Concomitant open posterior procedures and other indications for PAHA were excluded. Demographic data were collected with pre- and postoperative diagnosis, arthroscopic findings, type of impingement, location, associated procedures, and anatomical etiologies. Trigonal impingements were divided in os trigonal or Stieda and subgrouped as isolated, with flexor hallucis longus (FHL) disorders, with FHL plus other impingement, and with other impingement lesions. Results: A total of 111 ankles were studied-74 os trigonum and 37 Stieda. Isolated trigonal disorders accounted for 15.3% of PAIS (n = 17). Cases having associated conditions had a mode of 3 additional pathologies. FHL disorders were found in 69.4%, subtalar impingement in 32.4%, posteromedial ankle synovitis in 25.2%, posterolateral ankle synovitis in 22.5%, and posterior inferior tibiofibular ligament impingement in 19.8% of cases. Associated pathologies were observed in 58.6% of cases when FHL was not considered. Significant differences were noted comparing os and Stieda (isolated: 20.3% to 5.4%, P = .040; FHL plus others: 35.1% to 59.5%, P = .015). Conclusion: Trigonal bone (os trigonum or Stieda) was found to cause impingement in isolation in a small proportion of cases even when the FHL was considered part of the same disease spectrum. This should alert surgeons when considering removing trigonal impingement. Open approaches may limit the visualization and assessment of associated posterior ankle and subtalar pathoanatomy, thus possibly overlooking concomitant causes of PAIS. Level of Evidence: Level III, retrospective comparative study.

Outcomes of Surgical Treatment for Sural Neuritis: A Retrospective Case Series.

BACKGROUND: Somatic nerve pain is one of the most common complications following surgery of the foot and ankle but may also arise following traumatic injury or chronic nerve compression. The sural nerve is a commonly affected nerve in the foot and ankle; it is at risk given the proximity to frequently used surgical approaches, exposure to crush injuries, and traction from severe ankle inversion injuries. The purpose of this study is to investigate the outcomes of sural nerve neurectomy with proximal implantation for sural neuromas (SN) and chronic sural neuritis (CSN). METHODS: Patients that underwent neurectomy with proximal implantation (20 muscle, 1 adipose tissue) by 2 foot and ankle specialists for isolated SN- and CSN-related pain at a single tertiary institution were included. Demographic data, baseline outcomes including 36-Item Short Form Health Survey (SF-36), Foot and Ankle Ability Measure (FAAM), and visual analog scale (VAS) were recorded. Final follow-up questionnaires using Patient Reported Outcomes Measurement Information System (PROMIS) lower extremity function, pain interference (PI), and neuropathic pain quality, FAAM, and VAS were administered using REDCap. Perioperative factors including neuropathic medications, diagnostic injections, the use of collagen wraps, and perioperative ketamine were collected from the medical record. Descriptive statistics were performed and potential changes in patient-reported outcome measure scores were evaluated using Wilcoxon signed-rank tests. RESULTS: The 21 patients meeting inclusion criteria for this study had a median age of 47 years (interquartile range [IQR], 43-49) and had median follow-up duration of 33.7 months (IQR, 4.5-47.6). Median FAAM activities of daily living score improved from 40.6 (38.7-50.7) preoperatively to 66.1 (53.6-83.3) postoperatively, P = .032. FAAM sports scores improved from 14.1 (7.8-21.9) to 41.1 (25.0-60.9) postoperatively, P = .002. VAS scores improved from a median of 9.0 (8.0-9.0) to 3.0 (3.0-6.0), P < .001. At final follow-up, patients reported PROMIS lower extremity function score median of 43.8 (35.6-54.9), PROMIS neuropathic pain quality score of 54.1 (43.6-61.6), and PROMIS PI of 57.7 (41.1-63.8). Patients with both anxiety and depression reported less improvement in pain and physical. Other perioperative factors lacked sufficient numbers for statistical analysis. CONCLUSION: Sural nerve neurectomy and proximal implantation (20 muscle, 1 adipose) provided significant improvement in pain and function for patients with sural neuromas and chronic sural neuritis at median follow-up of 33.7 months. Anxiety and depression were associated with significantly poorer outcomes following surgery. Patients with CRPS as well as recent nicotine use tended to report less improvement in pain and worse function after surgery, although this sample size was too limited for statistical analysis of these variables. Further research is needed to identify the ideal surgical candidates and perioperative factors to optimize patient outcomes. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Risks Associated With Posterior Ankle Hindfoot Arthroscopy Complications.

BACKGROUND: The use of posterior ankle and hindfoot arthroscopy (PAHA) has been expanding over time. Many new indications have been reported in the literature. The primary objective of this study was to report the rate of PAHA complication in a large cohort of patients and describe their potential associations with demographical and surgical variables. METHODS: In this IRB-approved retrospective comparative study, patients who underwent posterior ankle and/or hindfoot arthroscopy in a single institution from December 2009 to July 2016 were studied. Three fellowship-trained orthopaedic foot and ankle surgeon performed all surgeries. Demographic data, diagnosis, tourniquet use, associated procedures, and complications were recorded. To investigate a priori factors predictive of neurologic complication after PAHA, univariate and multivariable logistic regression was utilized. Where appropriate, sparse events sensitivity analysis was tested by fitting models with Firth log-likelihood approach. RESULTS: A total of 232 subjects with 251 surgeries were selected. Indications were posterior ankle impingement (37%), flexor hallux longus disorders (14%), subtalar arthritis (8%), and osteochondral lesions (6%). Complications were observed in 6.8% (17/251) of procedures. Neural sensory lesions were noted in 10 patients (3.98%), and wound complications in 4 ankles (1.59%). Seven neurologic lesions resolved spontaneously and 3 required further intervention. In a multivariable regression model controlled for confounders, the use of accessory posterolateral portal was the significant driver for neurologic complications (odds ratio [OR] 32.19, 95% CI 3.53-293.50). CONCLUSION: The complication rate in this cohort that was treated with posterior ankle and/or hindfoot arthroscopy was 6.8%. Most complications were due to neural sensorial injuries (sural 5, medial plantar nerve 4, medial calcaneal nerve 1 ) and 3 required additional operative treatment. The use of an accessory posterolateral portal was significantly associated with neurologic complications. The provided information may assist surgeons in establishing diagnoses, making therapeutic decisions, and instituting surgical strategies for patients that might benefit from a posterior arthroscopic approach. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

The Effect of Progressive Lateral Column Lengthening in a Novel Stage II-B Flatfoot Cadaveric Model Evaluated Using Software-Guided Radiographic Measurements of Foot Alignment.

BACKGROUND: This work used software-guided radiographic measurement to assess the effects of progressive lateral column lengthening (LCL) on restoring alignment in a novel cadaveric model of stage II-B flatfoot deformity. METHODS: A stage II-B flatfoot was created in 8 cadaveric specimens by transecting the spring ligament complex, anterior deltoid, and interosseous talocalcaneal and cervical ligaments. Weightbearing computed tomographic (WBCT) scans were performed with specimens under 450 N of compressive load in the intact, flat, and 6-, 8-, and 10-mm lateral column-lengthening conditions. Custom software-guided radiographic measurements of the lateral talo-first metatarsal (Meary) angle, anteroposterior talo-first metatarsal angle, naviculocuneiform overlap, and 2 new measures (plantar fascia [PF] distance and angle) were recorded on digitally reconstructed radiographs. Four anonymized analysts performed measurements twice. Intra- and interobserver agreement was assessed using intraclass correlation coefficients (ICCs). RESULTS: Six-millimeter LCL restored alignment closest to the intact foot in this new cadaveric model, whereas 10-mm lengthening tended toward overcorrection. The PF line displaced laterally in the flatfoot condition, and LCL restored the PF line to a location beneath the talonavicular joint. Interobserver agreement was excellent for PF distance (ICC = 0.99) and naviculocuboid overlap (ICC = 0.91), good for Meary angle (ICC = 0.81) and PF angle (ICC = 0.69), and acceptable for the talonavicular coverage angle (ICC = 0.65). CONCLUSION: In this stage II-B cadaveric flatfoot model, cervical ligament transection was essential to create deformity after the medial hindfoot ligaments were transected. Software-guided radiographic measurement proved reliable; standardized implementation should improve comparability between studies of flatfoot deformity. The novel PF distance performed most consistently (ICC = 0.99) and warrants further study. With this model, we found that a 6-mm LCL restored alignment closest to the intact foot, whereas 10-mm lengthening tended toward overcorrection. CLINICAL RELEVANCE: Future joint-sparing flatfoot corrections may consider using a relatively small LCL combined with other bony and/or anatomic ligament/tendon reconstructions.

The Role of Anterior Ankle Arthroscopy in the Management of Ankle Arthritis: Literature Review, Patient Evaluation, Goals of Treatment and Technique.

The current body of literature regarding anterior ankle arthroscopic debridement for anterior ankle impingement (AAI) cases with ankle osteoarthritis (OA) has significant limitations. The reported poor outcomes lack the necessary rigor in patient selection, preoperative evaluations and in most reports, the use of a systematic operative approach. Furthermore, the lack of postoperative evaluation by authors using physical examination and radiologic studies to determine the etiology of ongoing pain leaves open the possibility that treatment of impingement was incomplete. For these reasons, it would be inappropriate to conclude that anterior arthroscopic debridement has no role in the treatment of ankle OA. Critical analysis of some studies provides encouragement that this can be a useful intermediate treatment of appropriately selected patients with AAI and ankle OA. The level of required detail in the physical examination and radiologic evaluation is much greater than for more straight-forward cases of soft tissue impingement or simple osteophyte impingement in otherwise healthy joints. The success of the treatment requires a systematic approach to the evaluation and performance of the procedure, which is perhaps why results in the literature have been suboptimal in most series. Future studies should apply this rigorous approach to patient selection, procedure performance, and postoperative analysis to best clarify which patients can be best served with this procedure as part of the various intermediate treatment options for ankle OA.

Intra- and Interobserver Reliability of the New Classification System of Progressive Collapsing Foot Deformity.

BACKGROUND: Historical concept of flatfoot as posterior tibial tendon dysfunction (PTTD) has been questioned. Recently, the consensus group published a new classification system and recommended renaming PTTD to Progressive Collapsing Foot Deformity (PCFD). The new PCFD classification could be effective in providing comprehensive information on the deformity. To date, there has been no study reporting intra- and interobserver reliability and the frequency of each class in PCFD classification. METHODS: This was a single-center, retrospective study conducted from prospectively collected registry data. A consecutive cohort of PCFD patients evaluated from February 2015 to October 2020 was included, consisting of 92 feet in 84 patients. Classification of each patient was made using characteristic clinical and radiographic findings by 3 independent observers. Frequencies of each class and subclass were assessed. Intraobserver and inteobserver reliabilities were analyzed with Cohen kappa and Fleiss kappa, respectively. RESULTS: Mean sample age was 54.4, 38% was male and 62% were female. 1ABC (25.4%) was the most common subclass, followed by 1AC (8.7%) and 1ABCD (6.9%). Only a small percentage of patients had isolated deformity. Class A was the most frequent component (89.5%), followed by C in 86.2% of the cases. Moderate interobserver reliability (Fleiss kappa = 0.561, P < .001, 95% CI 0.528-0.594) was found for overall classification. Very good intraobserver reliability was found (Cohen kappa = 0.851, P < .001, 95% CI 0.777-0.926). CONCLUSION: Almost half (49.3%) of patients had a presentation dominantly involving the hindfoot (A) with various combinations of midfoot and/or forefoot deformity (B), (C) with or without subtalar joint involvement (D). The new system may cover all possible combinations of the PCFD, providing a comprehensive description and guiding treatment in a systematic and individualized manner, but this initial study suggests an opportunity to improve overall interobserver reliability. LEVEL OF EVIDENCE: Level III, retrospective diagnostic study.

Multiplanar instability of the first tarsometatarsal joint in hallux valgus and hallux rigidus patients: a case-control study.

BACKGROUND: Hypermobility of the first ray has been considered associated with various forefoot diseases including hallux valgus (HV) and hallux rigidus (HR). Weightbearing CT scan can be a reliable method for analysis of the first tarsometatarsal (TMT) joint in axial, sagittal, and coronal planes. Our objective was to comparatively investigate signs of instability of the first TMT joint on weightbearing CT between three groups (control, HV, and HR). METHODS: In this single-centre, retrospective, case-control study, 27 HV patients (30 feet; mean age 54.2 years), 26 HR patients (30 feet; mean age 56.6 years), and 30 controls (30 feet; mean age; 43 years) were enrolled. Measurements of signs of instability were performed in multiplanes including first TMT angle, dorsal translation of the first metatarsal (M1) at the first TMT joint, plantar distance between the medial cuneiform (C1) and M1 in sagittal plane, hallux valgus angle (HVA), intermetatarsal angle (IMA) in axial plane, rotational profiles of C1 and M1 in coronal plane. Analysis of variance (ANOVA) test and chi-square test were performed to compare each parameter between the three groups. Interobserver reliabilities were assessed using interclass correlation coefficients (ICCs). RESULTS: The HV group had significantly increased first TMT angle (0.23° in controls, 1.15° in HV, 0.19° in HR, p < 0.001), HVA (7.52°, 33.50°, 11.21°, p < 0.001), IMA (9.46°, 16.98°, 11.87°, p < 0.001), C1-M1 angle (22.44°, 29.46°, 23.74°, p < 0.001), and rotational profile of the distal M1 (7.06°, 17.88°, 9.85°, p < 0.001) compared with the control and HR groups. Dorsal translation of M1 (23% in controls, 63% in HV, 70% in HR, p < 0.001) was frequently found in the HV and HR groups with significantly increased plantar distance (0.37 mm, 1.14 mm, 1.46 mm, p < 0.001) compared with controls. CONCLUSIONS: Multiplanar instability of the first TMT joint was confirmed using weightbearing CT in HV and HR groups compared with controls. HV group demonstrated instability mainly in sagittal and axial planes; HR group had sagittal instability predominantly. Our measurement of rotational instability at the first TMT joint was not able to detect differences between groups. A surgical correction of the instability at the first TMT joint can be an option to address HV and HR. CLINICAL RELEVANCE: First ray hypermobility at the first TMT joint is an important consideration when addressing HV and HR, a surgical correction of the instability at the first TMT joint should be taken in consideration as an option.

State of the Art in Treatment of Chronic Medial Ankle Instability.

Chronic deltoid instability (CDI), or medial ankle instability, can happen following traumas of the foot and ankle, predominantly rotational injuries. CDI is frequently underdiagnosed or misdiagnosed. Long-term residual instability can lead to ankle posttraumatic arthritis. Adequate assessment of patients with suspected CDI is paramount. Conservative treatment can be tried for stable or mildly unstable cases, but surgical treatment is usually needed for the more severely unstable patients, or when conservative measures fail. Few reconstruction techniques have been proposed in the setting of posttraumatic CDI. This article describes our preferred technique for reconstruction of the deep components of the deltoid ligament.

Three-Dimensional Distance and Coverage Maps in the Assessment of Peritalar Subluxation in Progressive Collapsing Foot Deformity.

BACKGROUND: Progressive collapsing foot deformity (PCFD), formerly termed adult-acquired flatfoot deformity, is a complex 3-dimensional (3D) deformity of the foot characterized by peritalar subluxation (PTS). PTS is typically measured at the posterior facet, but recent studies have called this into question. The objective of this study was to use 3D distance mapping (DM) from weightbearing computed tomography (WBCT) to assess PTS in patients with PCFD and controls. We hypothesized that DMs would identify the middle facet as a superior marker for PTS. METHODS: We analyzed WBCT data of 20 consecutive stage I patients with PCFD and 10 control patients with a novel DM technique to objectively characterize joint coverage across the entire peritalar surface, including both articular and nonarticular regions. Joint coverage was defined as the percentage of articular area with DMs <4 mm and impingement when distances were <0.5 mm. Comparisons were performed with independent t tests or Wilcoxon tests. P values <.05 were considered significant. RESULTS: Overall, coverage was decreased in articular regions and impingement was increased in nonarticular regions of patients with PCFD with a significant increase in uncoverage in the middle (46.6%, P < .001) but not anterior or posterior facets. Significant increases in sinus tarsi coverage were identified (98.0%, P < .007) with impingement in 6 of 20 patients with PCFD. Impingement of the subfibular region was noted in only 1 of 20 cases but narrowing greater than 2 standard deviations was noted in 17 of 20 patients. CONCLUSION: Objective DMs identified significant markers of PTS in the middle but not posterior or anterior facets. We confirmed prior 2-dimensional data that suggested uncoverage of the middle facet provided a more robust and consistent measure of PTS than measures in the posterior facet. LEVEL OF EVIDENCE: Level III, case-control study.

A Multi-Functional Implant Induces Bone Formation in a Diabetic Model.

Patients with diabetes mellitus (DM) have defective healing of bone fractures. It was previously shown that nonviral gene delivery of plasmid DNA (pDNA) that independently encodes bone morphogenetic protein-2 (BMP-2) and fibroblast growth factor-2 (FGF-2), acts synergistically to promote bone regeneration in a DM animal model. Additionally, both insulin (INS) and the hormonally active form of vitamin D3, 1α,25-dihydroxyvitamin D3 (1α,25(OH)2 D3 ) (VD3) have independently been shown to play key roles in regulating bone fracture healing in DM patients. However, these individual therapies fail to adequately stimulate bone regeneration, illustrating a need for novel treatment of bone fractures in diabetic patients. Here, the ability of local delivery of INS and VD3 along with BMP-2 and FGF-2 genes is investigated to promote bone formation ectopically in Type-2 diabetic rats. A composite consisting of VD3 and INS is developed that contains poly(lactic-co-glycolic acid) microparticles (MPs) embedded in a fibrin gel surrounded by a collagen matrix that is permeated with polyethylenimine (PEI)-(pBMP-2+pFGF-2) nanoplexes. Using a submuscular osteoinduction model, it is demonstrated that local delivery of INS, VD3, and PEI-(pBMP-2+pFGF-2) significantly improves bone generation compared to other treatments, thusimplicating this approach as a method to promote bone regeneration in DM patients with bone fractures.

Diabetic Foot Surveillance Using Mobile Phones and Automated Software Messaging, a Randomized Observational Trial.

Background: Early detection of diabetic foot ulcers can improve outcomes. However, patients do not always monitor their feet or seek medical attention when ulcers worsen. New approaches for diabetic-foot surveillance are needed. The goal of this study was to determine if patients would be willing and able to regularly photograph their feet; evaluate different foot-imaging approaches; and determine clinical adequacy of the resulting pictures. Methods: We recruited adults with diabetes and assigned them to Self Photo (SP), Assistive Device (AD), or Other Party (OP) groups. The SP group photographed their own feet, while the AD group used a selfie stick; the OP group required another adult to photograph the patient's foot. For 8 weeks, we texted all patients requesting that they text us a photo of each foot. The collected images were evaluated for clinical adequacy. Numbers of (i) submitted and (ii) clinically useful images were compared among groups using generalized linear models and generalized linear mixed models. Results: A total of 96 patients consented and 88 participated. There were 30 patients in SP, 29 in AD, and 29 in OP. The completion rate was 77%, with no significant differences among groups. However, 74.1% of photographs in SC, 83.7% in AD, 92.6% in OP were determined to be clinically adequate, and these differed statistically significantly. Conclusions: Patients with diabetes are willing and able to take photographs of their feet, but using selfie sticks or having another adult take the photographs increases the clinical adequacy of the photographs.Level of Evidence: II.

Preliminary Experience with Conservative Sharp Wound Debridement by Nurses in the Outpatient Management of Diabetic Foot Ulcers: Safety, Efficacy, and Economic Analysis.

Background: Treatment of diabetes costs the United States an estimated $245 billion annually; one-third of which is related to the treatment of diabetic foot ulcers (DFUs). We present a safe, efficacious, and economically prudent model for the outpatient treatment of uncomplicated DFUs. Methods: 77 patients (mean age = 54 years, range 31 to 83) with uncomplicated DFUs prospectively enrolled from September 2008 through February 2012. All patients received an initial sharp debridement by one of two orthopaedic foot and ankle fellowship trained surgeons. Ulcer dressings, offloading devices, and debridement procedures were standardized. Patients were evaluated every two weeks by research nurses who utilized a clinical management algorithm and performed conservative sharp wound debridement (CSWD). Results: Average time to clinical healing was 6.0 weeks. There were no complications of CSWD performed by nurses. The sensitivity for the timely identification of wound deterioration was 100%, specificity = 86.49%, PPV = 68.75% and NPV = 100% with an overall accuracy of 89.58%. The estimated cost savings in this model by having nurses perform CSWD was $223.26 per encounter, which, when extrapolated to national estimates, amounts to $1.56 billion to $2.49 billion in potential annual savings across six to ten-week treatment periods, respectively. Conclusion: CSWD of DFUs by nurses in a vertically integrated multidisciplinary team is a safe, effective, and fiscally responsible clinical practice. This clinical model on a national scale could result in significant healthcare savings. Surgeons and other licensed independent practitioners would have more time for evaluating and treating more complex and operative patients; nurses would be practicing closer to the full extent of their education and training as allowed in most states.Level of Evidence: III.

Assessment of Posterior and Middle Facet Subluxation of the Subtalar Joint in Progressive Flatfoot Deformity.

BACKGROUND: Adult acquired flatfoot deformity (AAFD) is a complex 3-dimensional pathology characterized by peritalar subluxation (PTS) of the hindfoot. For many years, PTS was measured at the posterior facet of the subtalar joint. More recently, subluxation of the middle facet has been proposed as a more accurate and reliable marker of symptomatic AAFD, enabling earlier detection. The objective of this study was to compare the amount of subluxation between the medial and posterior facets in patients with AAFD. METHODS: In this institutional review board-approved retrospective comparative study, a total of 76 patients with AAFD (87 feet) who underwent standing weightbearing computed tomography (WBCT) as a standard baseline assessment of their foot deformity were analyzed. Two blinded fellowship-trained orthopedic foot and ankle surgeons with >10 years of experience measured subtalar joint subluxation (as a percentage of joint uncoverage) at the both posterior and middle facets. One of the readers also measured the foot and ankle offset (FAO). PTS measurements were performed at the sagittal midpoint of the articular facets using coronal plane WBCT images. Intra- and interobserver agreement was measured for PTS measurements using the intraclass correlation coefficient (ICC). The intermethod agreement between the posterior and middle facet subluxation was assessed using Spearman's correlation and bivariate analysis. Paired comparison of the measurements was performed using the Wilcoxon test. A multivariate analysis and a partition prediction model were used to assess influence of PTS measurements on FAO values. P values of <.05 were considered significant. RESULTS: ICCs for intra- and interobserver reliabilities were 0.97 and 0.93, respectively, for posterior and 0.99 and 0.97, respectively, for middle facet subluxation. The intermethod Spearman's correlation between subluxation of the posterior and middle facets was measured at 0.61. In a bivariate analysis, both measurements were found to be significantly and linearly correlated (P < .0001; R2 = 0.42). Measurements of middle facet subluxation were found to be significantly higher than those for posterior facet subluxation, with a median difference (using the Hodges-Lehman factor) of 17.7% (P < .001; 95% CI, 10.9%-23.6%). We also found that for every 1% increase in posterior facet subluxation there was a corresponding 1.6-fold increase in middle facet subluxation. Only middle facet subluxation measurements were found to significantly influence FAO calculations (P = .003). The partition prediction model demonstrated that a middle facet subluxation value of 43.8% represented an important threshold for increased FAO. CONCLUSION: This study is the first to compare WBCT measurements of subtalar joint subluxation at the posterior and middle facets as markers of PTS in patients with AAFD. We found a positive linear correlation between the measurements, with subluxation of the middle facet being significantly more pronounced than that of the posterior facet by an average of almost 18%. This suggests that middle facet subluxation may provide an earlier and more pronounced marker of progressive PTS in patients with AAFD. LEVEL OF EVIDENCE: Level III, retrospective comparative cohort study.

3D Talar Kinematics During External Rotation Stress Testing in Hindfoot Varus and Valgus Using a Model of Syndesmotic and Deep Deltoid Instability.

BACKGROUND: External rotation stress (ERS) identifies ankle instability after fibular reduction of rotational ankle injuries. Combined hindfoot and ankle motions and an inconsistent starting position could mask differing degrees of instability resulting from syndesmotic and/or deltoid ligament disruption. The goal of this work was to use full 3D talar kinematics to evaluate the effects of hindfoot orientation and foot starting position during ERS on the ability to detect instability caused by ligament disruptions. METHODS: Six cadaveric ankles with metallic fiducial markers were CT scanned in neutral and 3 stress positions: varus hindfoot internal rotation stress (IRS-var), valgus hindfoot ERS (ERS-val), and varus hindfoot ERS (ERS-var). Scans were obtained in stress positions after transecting the deep deltoid ligament (tDDL) and then the syndesmotic ligaments (tDDL+Syn). Talar rotations and translations were computed in the axial, coronal, and sagittal planes in each stress position. Changes in a fixed center of rotation (CoR) relative to the intact sequence were calculated. RESULTS: Axial plane rotation beginning from IRS-var increased significantly for each level of ligamentous instability (P < .05 for all conditions) (10.9 degrees, intact; 14.1 degrees, tDDL; 22.7 degrees, tDDL+Syn during ERS-val; and 16.4 degrees, intact; 23.1 degrees, tDDL; 29.9 degrees, tDDL+Syn during ERS-var). With ERS-val, the talar CoR moved medially (3.6-5.4 mm) and posteriorly (0.5-5.2 mm); ERS-var moved anterior/laterally or posterior/medially depending on the specific ligamentous instability. With tDDL+Syn the ankle became grossly unstable and there were no clear trends in sagittal/coronal rotation or translation. CONCLUSION: An ERS test from internal to external rotation consistently differentiates between normal, tDDL, and tDDL+Syn. Talar CoR moved outside the mortise with ligamentous instability. CLINICAL RELEVANCE: Significant residual deep deltoid instability is likely underrecognized with current practice. The most discriminatory test for detecting such instability in our laboratory was an ERS test performed by internally rotating the foot to a hard, bony endpoint, positioning the hindfoot in varus, and then performing the entire external rotation maneuver while maintaining the varus hindfoot position.

Vancouver Foot and Ankle WNS (Wound, Nerve, and Systemic) Classification System for Foot and Ankle Orthopedic Surgery.

BACKGROUND: Adverse events require consistent recording to determine the effect of alternate treatments. This study was undertaken to evaluate the Vancouver Foot and Ankle WNS complication scale to capture complications (W: wound, N: nerve, S: systemic) to assist in outcome recording. METHODS: Interrater reliability was tested in 2 settings: (1) between 2 blinded clinicians in a live clinical setting and (2) between 8 orthopedic surgeons using case vignettes based on a retrospective analysis of 500 foot and ankle procedures performed at the Toronto Western Hospital, Department of Orthopaedics. The intrarater reliability of the WNS scale was tested in a single rater using the case vignettes. Inter- and intrarater reliability were assessed using the Fleiss and Cohen weighted kappa ( k), respectively and 95% confidence intervals (CIs). There was adequate power over 0.8. RESULTS: In the live clinical setting, the Cohen weighted k (95% CI) values for the W (0.935 [0.862, 1.01]), N (0.914 [0.752, 1.08]), and S (1 [1, 1]) parameters, indicating a near perfect level of agreement between raters. In the broader community of professional foot and ankle surgeons, the Fleiss k values (95% CI) had moderate agreement for the W (0.712 [0.688, 0.735]), N (0.775 [0.738, 0.811]), and high agreement for S (0.834 [0.802, 0.866]) parameters based on case vignettes. However, the Fleiss k values continued to indicate moderate to strong agreement between raters for all parameters. CONCLUSIONS: The WNS scale provided a standardized method of measuring foot and ankle surgical complications. There was at least moderate-strong interrater agreement for all parameters measured on case vignettes and excellent concordance in the live setting. LEVEL OF EVIDENCE: Level III, comparative series.

Effect of Posterior Malleolus Fracture on Syndesmotic Reduction: A Cadaveric Study.

BACKGROUND: Syndesmotic malreduction and fractures of the posterior malleolus negatively influence outcomes of rotational ankle fractures. Recent data have shown that posterior malleolus fixation contributes to the stability of the syndesmosis. The purpose of this study was to analyze syndesmotic reduction within the context of different sizes of posterior malleolus fracture fragments and different qualities of reduction. METHODS: A model of stage-IV supination-external rotation injury was created in 9 through-the-knee cadaveric specimens. The specimens were randomized to receive either a small (one-third of the incisura, n = 4) or a large (two-thirds of the incisura, n = 5) posterior malleolus fracture. High-resolution computed tomography (CT) scans were obtained of each intact specimen and then with clamp reduction of the syndesmosis along with a fracture fragment that was (1) unreduced, (2) anatomically reduced, or (3) fixed with a 4.8-mm-gap malreduction. Syndesmotic reduction in both the anterior-posterior and the medial-lateral direction was assessed relative to the intact specimen. RESULTS: Clamp reduction of the syndesmosis increased medial translation of the distal part of the fibula in the specimens with an unfixed or an anatomically fixed posterior malleolus fracture fragment and caused lateral displacement of the distal part of the fibula in the specimens with gap malreduction of the posterior malleolus fracture. Clamp reduction of the syndesmosis caused a slight anterior shift of the fibula in the specimens with a small unfixed or anatomically fixed posterior malleolus fracture fragment and caused a posterior shift of the fibula in the specimens with gap malreduction of a large fragment. CONCLUSIONS: The overall anterior-posterior reduction of the syndesmosis was generally unaffected by a posterior malleolus fracture except when there was malreduction of a large fragment. Medial-lateral syndesmotic reduction was affected by the conditions of the posterior malleolus fixation, with malreduction of the posterior malleolus leading to syndesmotic malreduction. CLINICAL RELEVANCE: When posterior malleolus fractures occur with syndesmotic injury, anatomic fracture reduction and fixation are paramount as they can affect syndesmotic reduction, especially with larger fragments.