Critical Portions of a Foot or Ankle Surgical Procedure From Patient and Surgeon Perspectives.

BACKGROUND: Over the past decade, overlapping procedures in orthopaedic surgery have come under increased public scrutiny. Central to this discussion is what should constitute a "critical portion" of any surgical procedure-a definition which may differ between patients and surgeons. This study therefore aimed to assess which components of three common foot and ankle procedures are considered "critical" from both the patient and surgeon perspectives. METHODS: For this survey-based study, questionnaires were administered to patients who presented to an orthopaedic foot and ankle clinic and separately administered to foot and ankle surgeons through e-mail. The questionnaires broached all steps involved in three common foot and ankle procedures: open reduction and internal fixation of ankle fracture, Achilles tendon repair, and ankle arthroscopy. Respondents were asked to characterize each step as "always critical," "often critical," sometimes critical," rarely critical," or "never critical." A combined "always critical" and "often critical" response rate of greater than 50% was used to define a step as genuinely critical. Patient and surgeon responses were thereafter compared using Mann-Whitney U and Kruskal-Wallis tests (P-value <0.05 was considered significant). RESULTS: Notably, both patients and surgeons considered informed consent, preoperative marking of the surgical site, preoperative time-out, surgical soft-tissue dissection, and certain procedure-specific steps (critical portions) of these procedures. By contrast, only patients considered skin incision and wound closure to be critical steps. CONCLUSION: Patients and surgeons were largely in agreement as to what should comprise the critical portions of several common foot and ankle procedures. Certain discrepancies did exist, however, such as skin incision and closure, and both groups were also in general agreement regarding what was not considered a critical component of these operations. Such findings highlight a potential opportunity for improved preoperative patient education and patient-physician communication. LEVEL OF EVIDENCE: Level IV: Evidence from well-designed case-control or cohort studies.

Arthroscopic all-inside ATiFL's distal fascicle transfer for ATFL's superior fascicle reconstruction or biological augmentation of lateral ligament repair.

PURPOSE: Tendon grafts are often utilized for reconstruction of the lateral ligaments unamenable to primary repair. However, tendon and ligaments have different biological roles. The anterior tibiofibular ligament's (ATiFL) distal fascicle may be resected without compromising the stability of the ankle joint. The aim of this study is to describe an all-arthroscopic and intra-articular surgical technique of ATiFL's distal fascicle transfer for the treatment of chronic ankle instability. METHODS: Five unpaired cadaver ankles underwent arthroscopic ATiFL's distal fascicle transfer using a non-absorbable suture and a knotless anchor. Injured or absent ATiFL's distal fascicle were excluded from the study. Following arthroscopy, the ankles were dissected and evaluated for entrapment of nearby adjacent anatomical structures. The ligament transfer was also assessed. The distance between the anterolateral (AL) portals and the superficial peroneal nerve (SPN) was measured and the shortest distance was reported. RESULTS: All specimens revealed successful transfer of the tibial origin of the ATiFL's distal fascicle onto the talar insertion of anterior talofibular ligament's (ATFL) superior fascicle. The fibular origin of the ATiFL's distal fascicle remained intact. There were no specimens with SPN or extensor tendon entrapment. The median distance between the proximal AL portal and SPN was 3.8 mm. The median distance between the distal AL portal and SPN was 3.9 mm. CONCLUSION: An all-arthroscopic approach to an ATiFL's distal fascicle transfer is a reliable method to reconstruct the ATFL's superior fascicle. Transfer of ATiFL's distal fascicle avoids the need for tendon harvest or allograft. The lack of injury to nearby adjacent structures suggests that it is a safe procedure. The clinical relevance of the study is that ATiFL's distal fascicle can be arthroscopically transferred to be used as a biological reinforcement of the ATFL repair, or as an ATFL reconstruction.

InternalBrace has biomechanical properties comparable to suture button but less rigid than screw in ligamentous lisfranc model.

PURPOSE: The aim of this study was to investigate the biomechanical properties of the InternalBrace for lisfranc injuries. METHODS: A Sawbone model was developed comparing screw, suture button and InternalBrace. RESULTS: When loaded in axial tension at 0.5 mm/s, the screw was stiffest (2,240 N/mm), while the InternalBrace (200 N/mm) was stiffer than the suture button (133 N/mm). Cyclic loading with 10,000 cycles of 69 N, 138 N, and 207 N showed the InternalBrace maintained stiffness, but fatigued earlier than the suture button. CONCLUSION: The mechanical properties of the InternalBrace support clinical use, but further studies are needed regarding early weight bearing.

Lateral Ankle Sprain and Chronic Ankle Instability.

A select 10-30% of patients with recurrent lateral ankle sprains develop chronic ankle instability (CAI). Patients with chronic ankle instability describe a history of the ankle "giving way" with or without pathological laxity on examination. Evaluation includes history, identification of predisposing risk factors for recurrent sprains, and the combination of clinical tests (eg, laxity tests) with imaging to establish the diagnosis. There are a variety of nonoperative strategies to address chronic ankle instability, which include rehabilitation and taping or bracing to prevent future sprains. Patients who fail conservative treatment are candidates for surgery. The anatomic approaches (eg, modified Broström) are preferred to nonanatomic procedures since they recreate the ankle's biomechanics and natural course of the attenuated ligaments. There is a growing interest in minimally invasive procedures via ankle arthroscopy that also address the associated intra-articular disorders. This article provides a review of chronic lateral ankle instability consisting of relevant anatomy, associated disorders, evaluation, treatment methods, and complications. LEVEL OF EVIDENCE: Level V, expert opinion.

Are piriformis reconstruction implants ideal for prophylactic femoral neck fixation?

OBJECTIVES: Prophylactic femoral neck fixation may be performed in the setting of geriatric diaphyseal femur fracture, pathologic or impending atypical femur fractures. Fixation constructs often utilize cephalomedullary implants with one or two proximal interlocking screws into the femoral head/neck. Variations in proximal femoral anatomy and implant design can interfere with the placement of two screws in the femoral head and neck. Our objective was to assess the strength of piriformis entry reconstruction implants with one versus two proximal interlock screws for prophylactic femoral neck fixation. METHODS: Thirty fourth generation synthetic femur models were separated into 5 groups. The control group was an intact femur, and the second group was an intact femur with an entry hole in the piriformis fossa. The remaining groups had an intramedullary nail placed with either 0, 1, or 2 screws placed into the femoral head and neck. Each femur was mechanically loaded along the mechanical axis through the femoral head. Load to failure and failure displacement were recorded. RESULTS: Mean load to failure was 5583 ± 543 N in the intact femur. Constructs with 2 screws had a significantly higher mean load to failure (3223 ± 474 N) compared to one screw constructs (2368 ± 280 N). All of the experimental groups remained significantly lower than the intact femur model (p < 0.05). CONCLUSION: Our results demonstrate that piriformis entry reconstruction implants have a significantly lower load to failure compared to an intact femur irrespective of screw construct. Further studies are needed to investigate this potential iatrogenic weakening.

The Effect of Radioscapholunate Fusion With and Without Distal Scaphoid and Triquetrum Excision on Capitolunate Contact Pressures.

PURPOSE: To determine the effects of motion-increasing modifications to radioscapholunate (RSL) arthrodesis on capitolunate contact pressure in cadaveric wrist specimens. METHODS: Ten fresh-frozen cadaveric wrists were dissected of all superficial soft tissue, potted in polymethyl-methacrylate, and the carpus exposed via a ligament-sparing capsulotomy. An RSL arthrodesis was simulated using 2 2.4-mm distal radius plates with locking screws. The distal scaphoid pole and triquetrum were removed with an osteotome and rongeur, respectively. Contact area, pressure, and force were measured in the capitolunate joint during the application of a 35-N uniaxial load using pressure-sensitive film. Measurements were obtained before and after simulated RSL fusion, following distal scaphoidectomy and after triquetrectomy. RESULTS: The combination of RSL fusion with distal scaphoid excision (DSE) increased contact forces in the capitolunate joint by 50% over controls. An RSL fusion, and RSL fusion with DSE and triquetrum excision (TE), exhibited intermediate levels of contact force between controls and RSL fusion with DSE. Capitolunate contact pressures were similar between all experimental groups. Contact area in the capitolunate joint increased by 43% after RSL fusion with DSE over intact specimen controls. Lastly, contact area in wrists with RSL fusion, and RSL fusion with DSE and TE, were elevated, but not significantly different from intact controls. CONCLUSIONS: A DSE performed at the time of RSL fusion results in increased midcarpal joint contact force and area, with resultant contact pressures unchanged. Triquetrectomy, which has been previously shown to improve range of motion, did not increase contact forces in the capitolunate joint. CLINICAL RELEVANCE: If a surgeon is contemplating performing an RSL arthrodesis with DSE, we recommend adding a triquetrectomy to improve motion because this does not add to the potentially deleterious effects of increased midcarpal contact force.

Hypoxic Preconditioning of Mesenchymal Stem Cells with Subsequent Spheroid Formation Accelerates Repair of Segmental Bone Defects.

Cell-based approaches for musculoskeletal tissue repair are limited by poor cell survival and engraftment. Short-term hypoxic preconditioning of mesenchymal stem cells (MSCs) can prolong cell viability in vivo, while the aggregation of MSCs into spheroids increases cell survival, trophic factor secretion, and tissue formation in vivo. We hypothesized that preconditioning MSCs in hypoxic culture before spheroid formation would increase cell viability, proangiogenic potential, and resultant bone repair compared with that of individual MSCs. Human MSCs were preconditioned in 1% O2 in monolayer culture for 3 days (PC3) or kept in ambient air (PC0), formed into spheroids of increasing cell density, and then entrapped in alginate hydrogels. Hypoxia-preconditioned MSC spheroids were more resistant to apoptosis than ambient air controls and this response correlated with duration of hypoxia exposure. Spheroids of the highest cell density exhibited the greatest osteogenic potential in vitro and vascular endothelial growth factor (VEGF) secretion was greatest in PC3 spheroids. PC3 spheroids were then transplanted into rat critical-sized femoral segmental defects to evaluate their potential for bone healing. Spheroid-containing gels induced significantly more bone healing compared with gels containing preconditioned individual MSCs or acellular gels. These data demonstrate that hypoxic preconditioning represents a simple approach for enhancing the therapeutic potential of MSC spheroids when used for bone healing. Stem Cells 2018;36:1393-1403.

Enoxaparin-induced skin necrosis at injection site after total knee arthroplasty.

Enoxaparin is a widely used low-molecular-weight heparin for perioperative thromboembolic prophylaxis. Enoxaparin-induced skin necrosis in the setting of arthroplasty has been rarely reported in the literature with varying outcomes and management decisions. Our patient developed skin necrosis at his injection site and thrombocytopenia 10 days following left total knee arthroplasty surgery and after receiving subcutaneous Lovenox injections postoperatively. The patient was started on an alternative anticoagulation based on a high suspicion for heparin-induced thrombocytopenia and the wound was monitored without surgical debridement. Our case highlights the key clinical management decisions when facing this potentially life-threatening adverse reaction.

Ultrasound Screening for Posterior Shoulder Dislocation in Infants with Persistent Brachial Plexus Birth Palsy.

BACKGROUND: Early detection of posterior shoulder dislocation in infants with brachial plexus birth palsy (BPBP) is essential, but it may be difficult to accomplish with physical examination alone. The aim of this study was to determine the prevalence of shoulder dislocation in patients with BPBP using ultrasound and to identify which physical examination measurements correlated most with dislocation in these patients. METHODS: This study was a retrospective review of data obtained in an ultrasound screening program of infants with BPBP born from January 2011 to April 2014. Physical examination included the use of the Active Movement Scale (AMS) and measurement of passive external rotation of the shoulder. Ultrasound measurements included PHHD (percentage of the humeral head displaced posterior to the axis of the scapula) and the alpha angle (intersection of the posterior scapular margin with a line tangential to the humeral head through the glenoid). Shoulder dislocation was defined as both a PHHD of >0.5 and an alpha angle of >30°. RESULTS: Of sixty-six infants who had undergone a total of 118 ultrasound examinations (mean, 1.8; range, 1 to 5), 19 (29%) demonstrated shoulder dislocation with the shoulder positioned in internal rotation; the dislocation was first detected between 2.1 and 10.5 months of age. Infants with a dislocated shoulder demonstrated significantly less mean passive external rotation in adduction (mean, 45.8° versus 71.4°, p < 0.001) and a greater difference between internal rotation and external rotation AMS scores (mean, 5.5-point versus 3.3-point difference, p < 0.001) than those without shoulder dislocation. Passive external rotation in adduction was a better measure for discriminating between dislocation and no dislocation (area under receiver operating characteristic curve [AUC] = 0.89) than was the difference between internal and external rotation AMS scores (AUC = 0.73). A cutoff of 60° of passive external rotation in adduction (≤60° versus° >60) yielded a sensitivity of 94% and a specificity of 69%. CONCLUSIONS: Shoulder dislocation is common in infants with BPBP; 29% of the infants presenting to our tertiary care center had a dislocation during their first year of life. Ultrasound shoulder screening is appropriate for infants with BPBP. If passive external rotation in adduction is used to determine which infants should undergo ultrasound, ≤60° should be utilized as the criterion to achieve appropriate sensitivity. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Interspinous process implantation for the treatment of neurogenic intermittent claudication.

BACKGROUND: Lumbar spinal stenosis (LSS) is a disabling medical condition in which narrowing of the spinal canal compresses the spinal cord and nerves causing a condition called neurogenic intermittent claudication (NIC). Decompressive spine surgery is the standard of care for patients who fail to improve with conservative management. However, oftentimes, patients who suffer from LSS are elderly individuals with multiple co-morbidities who cannot withstand the risks of decompressive surgery. X-Stop, a novel and minimally invasive FDA approved interspinous process implant, has come into the scene as an alternative to decompressive surgery, and can be inserted under local anesthetic with minimal blood loss. OBJECTIVES: Despite its growing support in medical literature as an effective and conservative treatment of NIC, X-Stop remains a fairly new form of treatment. The aim of this study is to assess the clinical efficacy of its use. PATIENTS AND METHODS: Fifty consecutive patients with at least two-year follow-up had a confirmed diagnosis of NIC secondary to LSS by computed tomography or magnetic resonance imaging (MRI) and subsequently received an X-Stop implant. Subjects' ages ranged from 64 to 95 with a mean age of 79, while the gender distribution comprised of 23 males and 27 females. Zurich Claudication Questionnaire (ZCQ) was used to assess patient outcome measures in three domains: physical function (PF), patient satisfaction (PS), and symptom severity (SS). The visual analog scale (VAS) was used to assess trends in pain with a scale from 0-10, with 0 defined as "pain-free" and 10 designated as "the worst pain imaginable". RESULTS: Compared to pre-op scores, PF, SS, and VAS scores for back, buttock and leg pain had a significant mean decrease at 6, 12, 24 months post-op (P < 0.05). Based on the ZCQ and VAS scores, a success rate of 79% (27.34), 78% (30.38) and 74% (17.23) were achieved at six months, 12 months, and 24 months respectively. CONCLUSIONS: X-Stop is a safe and effective treatment for NIC that provides marked relief of symptoms with sustained beneficial outcomes at up to two years of follow-up. In addition, X-Stop permits implantation under local anesthetic with minimal blood loss".