Interference screw versus suture button fixation for tibialis anterior tendon transfer: a biomechanical analysis.

Tibialis anterior tendon (TAT) transfer to the lateral cuneiform is commonly utilized to treat dynamic supination for relapsed clubfoot deformity. Traditional suture button fixation (SBF) may lead to skin necrosis at the button/skin interface. While interference screw fixation (ISF) would mitigate this concern, this fixation method has not been investigated in clubfoot patients. This study aims to investigate the performance of ISF versus SBF for TAT transfer in a cadaveric model. Ten matched pairs of cadaveric feet were obtained. One of each matched specimen underwent TAT transfer to the lateral cuneiform using ISF and the other underwent TAT transfer using SBF. For each ISF specimen, the tension of the transferred TAT required to bring the ankle to neutral was measured. This tension was then applied to both matched specimens using an MTS machine. Tension dissipation was measured after a 20-minute interval. In specimens with SBF, a load cell was positioned between the plantar skin and suture button to determine plantar skin pressure at the time of initial tension application. Average tension necessary to achieve neutral dorsiflexion was 49.4 N. Average tension dissipation after 20 min was significantly less in the IFS group (20 N versus 23.6 N, P = 0.02). No fixation failures occurred in either group. Average plantar foot skin pressure was 196.5 mmHg at initial tension application, exceeding thresholds for tissue ischemia. ISF allows for tendon tensioning at forces beyond those expected to result in skin necrosis with SBF with less dissipation of tension over time.

Clinical and Radiographic Assessment of Adult Function After Blount Disease in Childhood: An Exercise in Futility.

BACKGROUND: Few studies evaluate long-term function of patients with Blount disease. We sought to document patient radiographic and functional status 20 to 30 years after sugical treatment for infantile or adolescent Blount disease. METHODS: We reviewed the medical records and radiographs of patients operated at our institution for Blount disease between 1985 and 1995. Over a 4-year period, we recruited subjects for an IRB-approved call-back study. RESULTS: One hundred five patients were eligible for the call-back study. Thirty-one (30%) had a criminal record, 18 of sufficient gravity to preclude invitation to return. Of the remaining 87, 40 (46%) could not be contacted. Of 47 with valid contact information, 10 (21%) were reported as deceased (although this could not be objectively confirmed), 20 (43%) did not respond or failed to show for assessment, and 1 (2%) declined to participate. 16 subjects returned at average age 36, 22 to 31 years post-index surgery. Body mass index (BMI) averaged 45.8 (range 23.9 to 67.6). Physical Score correlated most strongly and inversely with BMI ( P <0.01). Satisfaction with life correlated strongly and inversely with mechanical axis deviation ( P =0.02) and radiographic osteoarthritis of the knee ( P =0.02), but not BMI. There also was no correlation between severity of radiographic osteoarthritis and mechanical axis deviation ( P =0.46) or BMI ( P =0.52). CONCLUSIONS: The small fraction of patients returning for evalutation minimize clinical conclusions that can be drawn from this study, despite an intensive 4-year effort to conduct it. Management of obesity and other socioeconomic characteristics are likely the most important aspects of treatment of patients with Blount disease. Our primary conclusion is that meaningful long-term functional studies of pediatric orthopaedic conditions will not be answered by retrospective call-back studies, and must be conducted within prospective registries and regular longitudinal follow-up. LEVEL OF EVIDENCE: III-Case-controlled study.

Functional Implications of Flat-Topped Talus Following Treatment of Idiopathic Clubfoot Deformity.

BACKGROUND: Though flatness of the talar dome (TD) is a potential consequence of operative and nonoperative clubfoot management, the functional impact of this deformity is not well understood. This study analyzes the relationship between TD morphology and ankle function at skeletal maturity in patients treated for idiopathic clubfoot during infancy. METHODS: 33 skeletally mature patients (average age 17.9 years) with 48 idiopathic clubfeet were identified. Weightbearing radiographs, gait analysis, and patient-reported outcomes using the Pediatric Orthopaedic Data Collection Instrument (PODCI) were obtained. Radius of curvature (ROC) of the TD and tibial plafond were measured along with other parameters of talar and calcaneal morphology. All measurements were correlated to PODCI scores and gait analysis data. RESULTS: Patients demonstrated marked variability in ROC of the TD (mean 30.8 mm, SD 13.6 mm), TD radius to talar length (R/L) ratio (mean 0.56, SD 0.28), opening angle of the TD (alpha angle) (mean 89.6°, SD 28.4°), and tibiotalar incongruity index (mean 0.18, SD 0.16). Increased tibiotalar incongruity index correlated with decreased maximum plantar flexion (r = ‒0.325, P = .02). A less acute alpha angle of the talar dome correlated with increased maximum ankle power generation (r = 0.321, P = .03) as did increased length of the talar neck (r = 0.358, P = .013). Increased tibiotalar incongruity index correlated negatively with PODCI global function domain scores (r = ‒0.490, P = .04; r = ‒0.381, P = .03, respectively), whereas length of the talar body correlated with higher global function scores (r = 0.376, P = .03) and lower pain scores (r = 0.350, P = .046). CONCLUSION: At skeletal maturity, flattening of the talar dome and tibiotalar incongruity on plain radiographs correlate modestly with gait changes, whereas tibiotalar incongruity and length of the talar body, not flatness of the talar dome, correlate with decreased patient-reported outcome scores. LEVEL OF EVIDENCE: Level III, prognostic.

Reconceptualizing the Juvenile Bunion.

BACKGROUND: The operative management of the juvenile bunion has not enjoyed the same level of success as its adult counterpart leading to the concern that we do not fully understand what differentiates these 2 deformities. This study aims to (1) characterize the radiographic and pedobarographic features commonly encountered in the juvenile bunion and (2) determine which of these radiographic or pedobarographic parameters correlate with patient-reported outcome (PRO) scores at the time of presentation. METHODS: An IRB-approved retrospective analysis of prospectively enrolled patients between 10 and 18 years of age with bunion deformities was performed at a single pediatric institution over a 4-year period. Standardized weight-bearing radiographs were used to determine hallux valgus angle (HVA), intermetatarsal angle, sesamoid position (SP), distal metatarsal articular angle (DMAA), and other radiographic parameters. Pedobarographic analysis was used to determine peak pressure, contact area, contact time, and pressure-time integral within 11 plantar regions. Foot-specific PRO measures were administered at the initial presentation. RESULTS: Thirty-two patients (57 feet) met the inclusion criteria of which56/57 feet (98.2%) had an elevated DMAA (average 21.4degrees±8.9 degrees), and 51/57 (89.4%) had a congruent joint. The DMAA correlated positively with the HVA (r=0.734 P <0.001), intermetatarsal angle (r=0.439 P =0.001), and SP (r=0.627 P <0.001). Pedobarographic analysis (available in 15/32 patients) demonstrated that the HVA correlated with increased second metatarsal head peak pressure (r=0.667 P =0.011) and pressure-time integral (r=0.604 P =0.002), which in turn was strongly correlated with worse PROs. Conversely, increased first metatarsal head contact area correlated with improved PROs. Analysis of radiographic measurements demonstrated that HVA and lateralized SP correlated significantly with worse PRO scores. CONCLUSIONS: Nearly all juvenile bunions have an elevated DMAA and a congruent joint. There is a clear correlation between the severity of radiographic and pedobarographic deformity and worse PRO scores at the time of presentation. We believe that the presence of elevated DMAA is the defining factor that differentiates the juvenile bunion from the deformity typically seen in adults. LEVEL OF EVIDENCE: III.

Curve Characteristics and Surgical Outcomes in Scoliosis Associated With Childhood Sternotomy or Thoracotomy.

BACKGROUND: The purpose of this study is to describe curve characteristics and postoperative outcomes in patients undergoing spinal fusion (SF) to treat thoracogenic scoliosis related to sternotomy and/or thoracotomy as a growing child. METHODS: A retrospective review of electronic medical records of all patients with Post-Chest Incision scoliosis treated with SF was performed at 2 tertiary care pediatric institutions over a 19-year period. Curve characteristics, inpatient, and outpatient postoperative outcomes are reported. RESULTS: Thirty-nine patients (62% female) were identified. Eighteen had sternotomy alone, 14 had thoracotomy alone, and 7 had both. Mean age at the time of first chest wall surgery was 2.5 years (range: 1.0 d to 14.2 y). Eighty-five percent of patients had a main thoracic curve (mean major curve angle 72 degrees, range: 40 to 116 degrees) and 15% had a main lumbar curve (mean major curve angle 76 degrees, range: 59 to 83 degrees). Mean thoracic kyphosis was 40 degrees (range: 4 to 84 degrees). Mean age at the time of SF was 14 years (range: 8.2 to 19.9 y). Thirty-six patients had posterior fusions and 3 had combined anterior/posterior. Mean coronal curve correction measured at the first postoperative encounter was 53% (range: 9% to 78%). There were 5 (13%) neuromonitoring alerts and 2 (5%) patients with transient neurological deficits. Mean length of hospital stay was 9±13 days. At an average follow-up time of 3.1±2.4 years, 17 complications (10 medical and 7 surgical) were noted in 9 patients for an overall complication rate of 23%. There was 1 spinal reoperation in the cohort. 2/17 (12%) complications were Clavien-Dindo-Sink class III and 5/17 (29%) were class IV. CONCLUSION: Kyphotic thoracic curves predominate in patients with Post-Chest Incision scoliosis undergoing SF. Although good coronal and sagittal plane deformity can be expected after a fusion procedure, postoperative complications are not uncommon in medically complex patients, often necessitating longer postoperative stays. LEVEL OF EVIDENCE: Level III.

The Efficacy of Intra-articular Subtalar Steroid Injection for Symptomatic Talocalcaneal Coalitions: A 30-Year Single Institution Experience.

PURPOSE: While intra-articular steroid injection has been used anecdotally in patients with symptomatic talocalcaneal coalitions recalcitrant to traditional conservative modalities, the ability of this treatment to provide symptomatic relief and obviate or delay surgical intervention remains unknown. The purpose of this study is, therefore, to assess the treatment efficacy of intra-articular subtalar steroid injection in children with symptomatic talocalcaneal coalitions. METHODS: A retrospective study of all patients with isolated subtalar coalitions was performed at a single pediatric orthopaedic institution over a 30-year period. Radiographs were analyzed to identify the type of coalition (osseous or nonosseous), presence of any posterior facet involvement, and presence of a planovalgus foot deformity. Patients who underwent a subtalar joint steroid injection after failing other conservative treatments were identified and compared with those who did not receive an injection as part of their nonoperative management with regard to the need for ultimate surgical intervention and the time from presentation to surgery when applicable. RESULTS: A total of 83 patients (125 feet) met inclusion criteria, of whom 25 patients (34 feet) received a subtalar steroid injection. When compared with the 58 patients (91 feet) treated with standard nonoperative modalities, there were no differences with regard to sex, age at presentation (12.4 and 12.3 y, respectively), facet involvement, type of coalition, or the presence of a planovalgus deformity. In all, 12/34 (35%) feet in the injection group eventually elected surgical intervention compared with 36/91 (39%) feet that did not receive an injection (P=0.72). For those patients ultimately selecting surgical intervention, the average time from initial presentation to surgery was 878 days in the injection group versus 211 days in the noninjection group (P<0.001). CONCLUSIONS: While subtalar steroid injection can alleviate symptoms in some patients with a talocalcaneal coalition, this intervention does not appear to decrease the need for surgery when compared with traditional nonoperative therapies. In patients failing other forms of conservative treatment, subtalar steroid injections can delay surgical intervention by an average of nearly 2 years. LEVEL OF EVIDENCE: Level-III-therapeutic study.

The Ponseti Method for the Treatment of Clubfeet Associated With Amniotic Band Syndrome: A Single Institution 20-Year Experience.

BACKGROUND: Amniotic band syndrome (ABS) is a congenital disorder resulting in fibrous bands that can cause limb anomalies, amputations, and deformities. Clubfoot has been reported in up to 50% of patients with ABS. The purpose of this study is to compare treatment characteristics and outcomes of clubfoot patients with ABS to those with idiopathic clubfoot treated with the Ponseti method. METHODS: An Institution Review Board (IRB) approved retrospective review of prospectively gathered data was performed at a single pediatric hospital over a 20-year period. Patients with either idiopathic clubfeet or clubfeet associated with concomitant ABS who were <1 year of age and treated by the Ponseti method were included. Initial Dimeglio score, number of casts, need for heel cord tenotomy, recurrence, and need for further surgery were recorded. Outcomes were classified as "good" (plantigrade foot±heel cord tenotomy), "fair" (need for a limited procedure), or "poor" (need for a full posteromedial release). RESULTS: Forty-three clubfeet in 32 patients with ABS, and 320 idiopathic clubfeet in 215 patients were identified. Average age at last follow up was not different between ABS and idiopathic cohorts (7.4 vs. 5.2 y, P=0.233). Average Dimeglio score was lower in the ABS cohort (12.3 vs. 13.7, P=0.006). Recurrence rate was significantly higher in the ABS (62.8%) compared with idiopathic cohort (37.2%) (P=0.001). Clinical outcomes were significantly better in the idiopathic cohort (69.4% "good", 26.9% "fair", 3.8% "poor") compared with the ABS cohort (41.9% "good", 34.9% "fair", and 23.3% "poor") (P<0.001). Within the ABS cohort, no significant differences in clinical outcomes were found based upon location, severity, or presence of an ipsilateral lower extremity band. CONCLUSION: Clubfeet associated with ABS have higher rates of recurrence, a greater need for later surgery, and worse clinical outcomes than idiopathic clubfeet. This information may prove helpful in counseling parents of infants with ABS associated clubfeet. LEVEL OF EVIDENCE: Level III.

Do We Really Need to Worry About Calcaneocuboid Subluxation During Lateral Column Lengthening for Planovalgus Foot Deformity?

BACKGROUND: Although lengthening of the lateral column through an osteotomy of the anterior calcaneus is an integral component of flatfoot reconstruction in younger patients with flexible planovalgus deformities, the procedure has been implicated in iatrogenic calcaneocuboid (CC) subluxation and subsequent degenerative changes at the CC articulation. The purpose of this study is to characterize alterations at the CC joint after lateral column lengthening (LCL) and determine if Steinmann pin stabilization of the CC joint before distraction maintains a normal relationship. METHODS: Seven matched pairs of fresh-frozen cadaveric feet underwent preprocedure plain radiography and cross-sectional computed tomography (CT) imaging. LCL by osteotomy through the anterior calcaneus was then performed. One foot of each matched pair had a single smooth Steinmann pin placed centrally across the CC joint before osteotomy distraction. Distraction across each osteotomy was then performed and maintained with a 12-mm porous titanium wedge. Repeat imaging was obtained and compared with preprocedure studies to quantify sagittal and rotational differences at the CC articulation. RESULTS: Following LCL, plain radiography demonstrated statistically significant increases in the percentage of the calcaneal articular surface dorsal to the superior aspect of the cuboid in both the pinned (8.2% vs. 17.6%, P=0.02) and unpinned (12.5% vs. 16.3%, P=0.04) specimens. No difference in the percentage of subluxation was found between the 2 groups after LCL. CT imaging demonstrated statistically significant increases in rotation between the calcaneus and cuboid after LCL in both the pinned (7.6±5.6 degrees, P=0.01) and unpinned (17±12.3 degrees, P=0.01) specimens. The degree of rotation was greater in unpinned specimens after LCL (P=0.043). CONCLUSIONS: Both sagittal and rotatory subluxation seem to occur at the CC joint after LCL regardless of pin stabilization. As a single pin would be expected to limit pure translation while having little effect on rotation, it is possible that the rotational changes identified on 3-dimensional imaging are interpreted as dorsal translation when viewed 2 dimensionally using plain radiography. Consideration should therefore be given to CC stabilization with 2 pins during LCL to prevent this rotatory subluxation. LEVEL OF EVIDENCE: Level V-cadaver study.

Effect of Lateral Column Lengthening on Subtalar Motion in a Cadaveric Model.

BACKGROUND: Although lengthening of the lateral column through a calcaneal neck osteotomy is an integral component of flatfoot reconstruction in younger patients with flexible planovalgus deformities, concern exists as to the effect of this intra-articular osteotomy on subtalar motion. The purpose of this study was to quantify the alterations in subtalar motion following lateral column lengthening (LCL). METHODS: The subtalar motion of 14 fresh-frozen cadaveric feet was assessed using a 3-dimensional motion capture system and materials testing system (MTS). Following potting of the tibia and calcaneus, optic markers were placed into the tibia, calcaneus, and talus. The MTS was used to apply a rotational force across the subtalar joint to a torque of 5 Nm. Abduction/adduction, supination/pronation, and plantarflexion/dorsiflexion about the talus were recorded. Specimens then underwent LCL via a calcaneal neck osteotomy, which was maintained with a 12-mm porous titanium wedge. Repeat subtalar motion analysis was performed and compared to pre-LCL motion using a paired t test. RESULTS: No statistically significant differences in subtalar abduction/adduction (10.9 vs 11.8 degrees, P = .48), supination/pronation (3.5 vs 2.7 degrees, P = .31), or plantarflexion/dorsiflexion (1.6 vs 1.0 degrees, P = .10) were identified following LCL. CONCLUSION: No significant changes in subtalar motion were observed following lateral column lengthening in this biomechanical cadaveric study. CLINICAL RELEVANCE: Although these findings do not obviate concerns of clinical subtalar stiffness following lateral column lengthening for planovalgus deformity correction, they suggest that diminished postoperative subtalar motion, when it occurs, may be due to soft tissue scarring rather than alterations of joint anatomy.