Dual Semitendinosus Allograft Reconstruction of Chronic Achilles Tendon Ruptures: Operative Technique and Outcomes.

BACKGROUND: Dual semitendinosus allograft reconstruction of chronic Achilles tendon ruptures has several potential benefits including superior tensile strength compared with a turndown construct and avoidance of the morbidity and operative time associated with autograft augmentation. We present a series of chronic Achilles tendon ruptures reconstructed with dual semitendinosus allograft. METHODS: We retrospectively reviewed the charts of patients aged 18 years and older who underwent reconstruction of chronic Achilles tendon ruptures using dual semitendinosus allograft. The primary outcome of this study was to evaluate the need for revision surgery. Secondary outcomes included patient-reported outcomes, for which Achilles Tendon Rupture Scores (ATRS) were collected at final follow-up. Nine patients with a mean age of 58.9 (range, 43-75) years met inclusion criteria. RESULTS: Median follow-up was 66 months (range, 27-121 months). One patient (11.1%) required revision reconstruction after sustaining graft failure 9.5 years after her index procedure, and 1 patient reported a poor ATRS score at the 27-month final follow-up despite an intact surgical repair. At final follow-up, no patient required the use of an assistive device for ambulation or a walking boot. The median ATRS at final follow-up was 93 (range, 30-100). DISCUSSION: Good clinical outcomes without rerupture were observed in 7 of 9 patients (77.8%) at short- to midterm follow-up, suggesting that dual semitendinosus allograft reconstruction is a viable option for the reconstruction of chronic Achilles tendon tears. LEVEL OF EVIDENCE: Level IV, case series.

Staple-Plate Plus Screw vs Screw Alone in Talonavicular Arthrodesis: A Cadaveric Biomechanical Study.

BACKGROUND: This study evaluated whether the addition of a nitinol staple-plate to a single cannulated screw increased the mechanical stability for a talonavicular fixation construct. METHODS: Twenty matched pairs of cadaveric feet were randomized to fusion with either a single 5.5-mm cannulated screw or a screw and a plate with 2 screws and a slot with an 18-mm nitinol staple. After in situ fusion procedure, the talonavicular joint complex was dissected free and the ends were embedded in epoxy. The specimens were then cyclically loaded on a servohydraulic load frame (1000 cycles at 20 N, increasing at intervals of 20 N until failure), half of them for cantilever bending and the other half for torsion. RESULTS: In the bending arm of the study, the staple-plate group showed significantly higher stiffness, failure load, and cycles to failure. In the torsion arm of the study, the staple-plate group also had higher cycles to failure, stiffness in external rotation, and torque to failure. No significant difference was noted in stiffness in internal rotation. CONCLUSION: We found a significant increase in stability of the talonavicular joint when a nitinol staple-plate construct was placed to augment a single cannulated screw for the purpose of a talonavicular fusion. CLINICAL RELEVANCE: This information may be helpful to surgeons in implant selection for this common arthrodesis procedure.

Randomized Controlled Trial of Micronized Dehydrated Human Amnion/Chorion Membrane (dHACM) Injection Compared to Placebo for the Treatment of Plantar Fasciitis.

BACKGROUND: Failure of conservative management to reduce/eliminate symptoms of plantar fasciitis (PF) may indicate need for advanced treatments. This study reports Level 1 evidence supporting 3-month safety and efficacy of micronized dehydrated human amnion/chorion membrane (dHACM) injection as a treatment for PF. METHODS: A prospective, single-blind, randomized controlled trial was conducted at 14 sites in the United States. Subjects were randomized to receive 1 injection, in the affected area, of micronized dHACM (n=73) or 0.9% sodium chloride placebo (n=72). Safety/efficacy assessments were conducted at 4 weeks, 8 weeks, 3 months, 6 months, and 12 months postinjection, using visual analog scale (VAS) for pain, Foot Function Index-Revised (FFI-R) score, and presence/absence of adverse events. Primary outcome was mean change in VAS score between baseline and 3 months expressed as difference in means for treatment versus control subjects. Secondary outcome was mean change in FFI-R score between baseline and 3 months expressed as difference in means for treatment versus control subjects. RESULTS: Baseline VAS scores were similar between groups. At the 3-month follow-up, mean VAS scores in the treatment group were 76% lower compared with a 45% reduction for controls ( P < .0001), FFI-R scores for treatment subjects had mean reduction of 60% versus baseline, whereas control subjects had mean reduction of 40% versus baseline ( P = .0004). Of 4 serious adverse events, none were related to study procedures. CONCLUSION: Pain reduction and functional improvement outcomes were statistically significant and clinically relevant, supporting use of micronized dHACM injection as a safe and effective treatment for PF. LEVEL OF EVIDENCE: Level I, prospective randomized trial.

Distribution of Subchondral Bone Puncture Strength in the Talus and Tibial Plafond: A Biomechanical Study.

We investigated talus and tibial plafond subchondral bone puncture strength based on surface location. Puncture tests of the subchondral bone were performed in 9 equal zones on the articular surface of 12 cadaver specimens aged 49.1 years (range, 36-56 years). Compressive load was applied through a microfracture awl at 2 mm/min. Puncture strength was defined as the first load drop in load-deflection curves. In the talus, zone 1 (215 ± 91 N) and zone 2, the anterior medial and anterior middle zones, had significantly greater puncture strength than zones 7, 8, and 9, the posterior medial, middle, and lateral zones (104 ± 43 N, 115 ± 43 N, and 102 ± 35 N, respectively; P < .001). In the tibial plafond, zone 3, the anterior-lateral zone, and zone 7, the posterior medial zone, had significantly greater strength than zone 8, the posterior middle zone (202 ± 72 N, 206 ± 121 N, and 112 ± 65 N, respectively; P < .001) These results suggest that the subchondral bone is significantly weaker to penetrative force in the posterior region than in the anterior region of the talar dome and of the tibial plafond. These findings may have implications for microfracture awl design and for understanding the complex anatomy and physiology of the ankle joint. LEVELS OF EVIDENCE: Controlled laboratory study.

Is Dual Semitendinosus Allograft Stronger Than Turndown for Achilles Tendon Reconstruction? An In Vitro Analysis.

BACKGROUND: Large Achilles tendon defects pose a treatment challenge. The standard treatment with a turndown flap requires a large extensile incision, puts the sural nerve at risk, and demands slow, careful rehabilitation. Dual allograft semitendinosus reconstruction is a new clinical alternative that has the theoretical advantages of a smaller incision, less dissection, and a stronger construct that may allow for faster rehabilitation. QUESTIONS/PURPOSES: In a cadaver biomechanical model, we compared the dual allograft semitendinosus reconstruction with the myofascial turndown in terms of (1) mechanical strength and resistance to deformation and (2) failure mechanisms in reconstruction of large segmental Achilles defects. METHODS: An 8-cm segmental Achilles defect was created in 18 cadaveric lower extremities, nine matched pairs without defect or previous surgery (mean age, 78.4 years; range, 60-97 years; three female and six male pairs). Femoral neck densitometry to determine bone mineral density found that all specimens except two were osteopenic or osteoporotic. Specimens in each pair were assigned to allograft or turndown reconstruction. The constructs were mounted on a load frame and differential variable reluctance transducers were applied to measure deformation. Specimens were preconditioned and then loaded axially. Tensile force and proximal and distal construct deformation were measured at clinical failure, defined as 10 mm of displacement, and at ultimate failure, defined as failure of the reconstruction. Failure mechanism was recorded. RESULTS: Tensile strength at time zero was higher in the allograft versus the turndown construct at clinical failure (156.9 ± 29.7 N versus 107.2 ± 20.0 N, respectively; mean difference, -49.7 N; 95% CI, -66.3 to -33.0 N; p < 0.001) and at ultimate failure (290.9 ± 83.2 N versus 140.7 ± 43.5 N, respectively; mean difference, -150.2 N; 95% CI, -202.9 to -97.6 N; p < 0.001). Distal construct deformation was lower in the turndown versus the allograft construct at clinical failure (1.6 ± 1.0 mm versus 4.7 ± 0.7 mm medially and 2.2 ± 1.0 mm versus 4.8 ± 1.1 mm laterally; p < 0.001). Semitendinosus allograft failure occurred via calcaneal bone bridge fracture in eight of nine specimens. All myofascial turndowns failed via suture pullout through the fascial tissue at its insertion. CONCLUSION: In this comparative biomechanical study, dual semitendinosus allograft reconstruction showed greater tensile strength and construct deformation compared with myofascial turndown in a cadaveric model of large Achilles tendon defects. CLINICAL RELEVANCE: Further study of dual semitendinosus allograft for treatment of severe Achilles tendon defects with cyclic loading and investigation of clinical results will better elucidate the clinical utility and indications for this technique.

Outcomes After Interpositional Arthroplasty of the First Metatarsophalangeal Joint.

BACKGROUND: For patients with hallux rigidus seeking a motion-sparing procedure, interposition arthroplasty is an alternative to fusion. The purpose of this study was to report patient outcomes after interpositional arthroplasty for hallux rigidus. METHODS: All patients undergoing interpositional arthroplasty at our institution from 2001 to 2014 were identified and a retrospective chart review was performed. Follow-up was conducted through a telephone survey to obtain survivorship, satisfaction, and functional scores. Survivorship of the interpositional arthroplasty procedure was defined as no subsequent surgery on the hallux after the index procedure. Patients were excluded for incomplete records. Complications were recorded. From 2001 to 2014, 183 patients were identified. Of these, 14 were excluded for incomplete data, leaving 169 patients. Of these, 133 had an average follow-up of 62.2 months (range, 24.3 months to 151.2 months). RESULTS: The overall failure rate was 3.8% (5/133). Patient-reported outcome was rated as excellent in 65.4% (87/133) or good in 24.1% (32/133) of patients and fair or poor in 10.5% (14/133) of patients. Of 133 patients, 101 (76%) were able to return to fashionable or regular footwear. The infection rate was 1.5% (2/133). Patient-reported cock-up deformity of the first metatarsophalangeal joint (MTPJ) occurred in 4.5% (6/133) of patients. In addition, 17.3% (23/133) of patients reported metatarsalgia of the second or third MTPJ at the time of final follow-up, and there was no significant difference between interposition types ( P = .441). CONCLUSION: Interpositional arthroplasty for hallux rigidus was found to have excellent or good results in most patients at a mean follow-up of 62.2 months. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Comparison of Suture-Based Anchors and Traditional Bioabsorbable Anchors in Foot and Ankle Surgery.

We compared the pullout strength of a suture-based anchor versus a bioabsorbable anchor in the distal fibula and calcaneus and evaluated the relationship between bone mineral density and peak load to failure. Eight paired cadaveric specimens underwent a modified Broström procedure and Achilles tendon reattachment. The fibula and calcaneus in the paired specimens received either a suture-based anchor or a bioabsorbable suture anchor. The fibular and calcaneal specimens were loaded to failure, defined as a substantial decrease in the applied load or pullout from the bone. In the fibula, the peak load to failure was significantly greater with the suture-based versus the bioabsorbable anchors (133.3 ± 41.8 N versus 76.8 ± 35.3 N; p = .002). No significant difference in load with 5 mm of displacement was found between the 2 groups. In the calcaneus, no difference in the peak load to failure was found between the 2 groups, and the peak load to failure with 5 mm of displacement was significantly lower with the suture-based than with the bioabsorbable anchors (52.2 ± 9.8 N versus 75.9 ± 12.4 N; p = .003). Bone mineral density and peak load to failure were significantly correlated in the fibula with the suture-based anchor. An innovative suture-based anchor had a greater peak load to failure compared with a bioabsorbable anchor in the fibula. In the calcaneus, the load at 5 mm of displacement was significantly lower in the suture-based than in the bioabsorbable group. The correlation findings might indicate the need for a cortical bone shelf with the suture-based anchor. Suture-based anchors could be a viable alternative to bioabsorbable anchors for certain foot and ankle procedures.

Inflammatory cytokines and cellular metabolites as synovial fluid biomarkers of posttraumatic ankle arthritis.

BACKGROUND: There is a paucity of research on posttraumatic ankle arthritis (PTAA). We aimed to identify synovial fluid PTAA biomarkers using cytokine analysis and metabolic profiling. METHODS: Ankle joint synovial fluid was obtained from 20 patients with PTAA and 20 patients with no ankle pain and no radiographic evidence of ankle arthritis (control group). Synovial fluid samples were analyzed for IFN-γ, TNF-α, MIP-1ß, MCP-1, IL-1ß, IL-1Ra, IL-4, IL-6, IL-8, IL-10, IL-13, and IL-15 using ELISA and for more than 3000 metabolites using liquid and gas chromatography with mass spectroscopy. To compare presence of cytokines and metabolites between groups, t tests were used. Random forest analysis was performed on metabolites to determine whether control and PTAA samples could be differentiated based on metabolic profile. RESULTS: IL-1Ra, IL-6, IL-8, IL-10, IL-15, and MCP-1 were significantly elevated in the PTAA group. In addition, 107 metabolites in the PTAA group were significantly altered, including derangement in amino acid, carbohydrate, lipid, and energy metabolism, extracellular matrix turnover, and collagen degradation. Random forest analysis yielded a predictive accuracy of 90% when using the metabolic profiles to distinguish between control and PTAA samples. CONCLUSION: This study identified inflammatory cytokines and metabolites present in the synovial fluid of PTAA. CLINICAL RELEVANCE: Several of these entities have previously been implicated in rheumatoid arthritis and osteoarthritis of the knee, but many could potentially be used as novel biomarkers of PTAA. Most importantly, the findings suggest that metabolites could be used to distinguish synovial fluid from patients with PTAA.

Stem cells in bone grafting: Trinity allograft with stem cells and collagen/beta-tricalcium phosphate with concentrated bone marrow aspirate.

The orthopedic foot and ankle surgeon needs bone grafts in the clinical situation of fracture healing and in bone-fusion procedures. This article briefly outlines thought processes and techniques for 2 recent options for the surgeon. The Trinity product is a unique combination of allograft bone and allograft stem cells. The beta-tricalcium phosphate and collagen materials provide an excellent scaffold for bone growth; when combined with concentrated bone marrow aspirate, they also offer osteoconductive and osteoinductive as well as osteogenerative sources for new bone formation.

In situ calcite formation in limestone-saturated water leaching of acid rock waste.

The result of leaching of a 75% acid rock/25% limestone column with limestone-saturated solution has shown that the pH of the effluent recovered from 2.5, after apparent loss of acid neutralizing capacity after 4 years with water leaching, to pH 7 in less than 3 years. Bulk assay results, XRD and SEM/EDS analyses of samples from the column at 384 weeks (pH 3.6) and 522 weeks (pH 6.9) during this recovery have suggested that this is due to formation in situ of fine calcite. Calcite, initially blended to the column material at 25 wt.% was not found in the XRD of the 384 week sample but is clearly found in the 522 week XRD. This increased calcite content appears to be derived from the limestone-saturated water as finely divided solid precipitated in the drying cycles in the column. This result is confirmed by assessment of the 522 week sample as non-acid forming. Loss of some reactive aluminosilicate minerals, formation of secondary, precipitated, surface-attached gypsum and loss of fine secondary jarosite occurs across this pH range but fine, surface-attached jarosite is still found in the 522 week sample implying relatively slow dissolution kinetics. In comparison with the 384 week sample, armouring of highly reacted pyrite particles by surface layers of iron oxyhydroxides and aluminosilicates has become more extensive at 522 weeks after return of the pH to neutral values. This is consistent with results from Freeport field samples from limestone blended test pads where pyrite armouring was also substantially increased at higher pH. The results suggest that it may be possible to effectively maintain neutral pH and passivate pyrite, reducing oxidation rates by more than an order of magnitude, using limestone-saturated solution dump feed rather than bulk limestone blending or covers.

Methods for estimation of long-term non-carbonate neutralisation of acid rock drainage.

In the long-term phase of an acid rock drainage (ARD) evolution profile, after any short-term neutralisation capacity provided by carbonate minerals is exhausted, the net acid release is a product of a declining acid generation rate (AGR) and a slower, long-term acid neutralisation rate mainly provided by gangue silicate minerals. At some point, the AGR and the non-carbonate acid neutralisation rate (ANRnc) will be similar. Matching of the AGR and ANRnc near 10mg H(2)SO(4)/kg/week is demonstrated in data from 10-year columns. This long-term neutralisation is not measured at present in any accepted assessment tests. Methods to estimate ANRnc, based on silicate mineralogy and solution assays from long-term column leach tests, are compared. Good agreement is demonstrated between rates measured from the solution assay data and those calculated from mineralogy using kinetic databases. More rigorous analysis of the leachate chemistry of selected long-term leach tests also suggests possible cover design criteria based on the maximum AGR that will maintain a pH>4 in leachate from ARD materials. The data show a distinct break at an AGR of 3mg H(2)SO(4)/kg/week, below which no leachate pH is less than 4. The results indicate that an AGR of 10t H(2)SO(4)/ha/year is conservative and a suitable cover design target for ARD control that would be matched by ANRnc.

Nerve disorders of the hallux.

Nerve disorders about the hallux can generate remarkable pain and dysfunction. Whether caused by soft tissue entrapment, trauma, iatrogenic injury, or from an idiopathic basis; nerve disorders are approached by careful history and examination followed by nonoperative treatment. In cases that do not respond, meticulous surgical management can be helpful in many cases.

Biomechanical analysis of tibial strength after harvesting unicortical tibial grafts of two different lengths.

BACKGROUND: It is not known whether the use of the proximal tibia as a source of strut graft compromises the strength of the tibia. Our hypothesis was that unicortical proximal tibial grafts in two different sizes would not significantly decrease the torsional strength of the tibia. MATERIALS AND METHODS: Ten matched pairs of human cadaver tibiae were stripped of all soft tissues. One tibia in each pair was randomly assigned to receive an osteotomy of 2 x 1.5 cm or 6 x 1.5 cm placed 1 cm dorsal to the tibial crest with the proximal graft edge 6 cm from the tibial plateau. Specimens were loaded at 720 N and in external rotational torque at 5 degrees per second to failure. Axial force or torque at failure were analyzed via T-test (p < or = 0.05). RESULTS: There was no significant difference in torque to failure between specimens with an osteotomy of 1.5 x 2 cm versus the matched intact specimens. Torque to failure for specimens with an osteotomy 1.5 x 6 cm was lower than that of the matched intact specimens (28.69 Nm +/- 4.2 Nm versus 60.95 Nm +/- 9.49 Nm; p = 0.01) and lower than that found in the 2-cm osteotomy group (p = 0.04). CONCLUSION: Torque to failure was significantly decreased with the larger 6-cm graft as compared with the intact tibia and with the graft 1.5 x 2 cm. The smaller graft did not result in a significant change in torsional strength of the tibia. CLINICAL RELEVANCE: Though this study cannot be extrapolated directly to the clinical setting, the longer graft tested in this study may raise concerns regarding the strength of the tibia after graft removal.