Faculty Bibliography

PURPOSE:To evaluate morphological alterations, microarchitectural disturbances, and the extent of bone marrow access to the subchondral bone marrow compartment using micro-computed tomography analysis in different bone marrow stimulation (BMS) techniques. METHODS:Nine zones in a 3 × 3 grid pattern were assigned to 5 cadaveric talar dome articular surfaces. A 1.00-mm microfracture awl (s.MFX), a 2.00-mm standard microfracture awl (l.MFX), or a 1.25-mm Kirschner wire (K-wire) drill hole was used to penetrate the subchondral bone in each grid zone. Subchondral bone holes and adjacent tissue areas were assessed by micro-computed tomography to analyze adjacent bone area destruction and communicating channels to the bone marrow. Grades 1 to 3 were assigned, where 1 = minimal compression/sclerosis; 2 = moderate compression/sclerosis; 3 = severe compression/sclerosis. Bone volume/total tissue volume, bone surface area/bone volume, trabecular thickness, and trabecular number were calculated in the region of interest. RESULTS:Visual assessment revealed that the s.MFX had significantly more grade 1 holes (P < .001) and that the l.MFX had significantly more poor/grade 3 holes (P = .002). Bone marrow channel assessment showed a statistically significant increase in the number of channels in the s.MFX when compared with both K-wire and l.MFX holes (P < .001). Bone volume fraction for the s.MFX was significantly less than that of the l.MFX (P = .029). CONCLUSIONS:BMS techniques using instruments with larger diameters resulted in increased trabecular compaction and sclerosis in areas adjacent to the defect. K-wire and l.MFX techniques resulted in less open communicating bone marrow channels, denoting a reduction in bone marrow access. The results of this study indicate that BMS using larger diameter devices results in greater microarchitecture disturbances. CLINICAL RELEVANCE:The current study suggests that the choice of a BMS technique should be carefully considered as the results indicate that smaller diameter hole sizes may diminish the amount of microarchitectural disturbances in the subchondral bone.

PURPOSE:To identify potential cysts using magnetic resonance imaging (MRI) after autologous osteochondral transplantation (AOT) for osteochondral lesions of the talus (OLTs) as well as to determine the effect of cysts on short-term clinical outcomes. METHODS:Eighty-nine MRI scans of 37 patients who had AOT for an OLT were evaluated. Radiographic variables examined included cyst presence, cyst location, bone edema, and cartilage integrity. Patient clinical variables recorded and examined for association with the presence of a cyst included gender, age, preoperative lesion size, size and number of osteochondral graft used, symptoms reported, and pre- and postoperative Foot and Ankle Outcome Score (FAOS) and Short Form-12 (SF-12) scores measured at final follow-up. RESULTS:Twenty-four patients (64.8%) had MRI evidence of cystic change after AOT for an OLT at a mean MRI follow-up time of 15 months after surgery (range 2-54). Patients with presence of a cyst after surgery were older (mean age, 42.7 years) than those without cysts (mean age, 32.7 years) (P = .041), and among patients with a cyst, older patients more often had involvement of the subchondral plate (57.3 v 36.7 years) (P < .001). No other variables associated with cyst formation had statistical significance. Mean patient FAOS scores increased from 50 (±19) preoperatively to 87 (±8) postoperatively. Mean SF-12 scores increased from 52 (±18) preoperatively to 85 (±6) postoperatively. Patients not identified as having a cyst had lower SF-12 (P = .028) and FAOS (P = .032) preoperative scores and more improvement in SF-12 (P = .006) and FAOS (P = .016) scores than patients with cysts. CONCLUSIONS:Postoperative cyst formation on MRI was found to be a common occurrence after AOT for OLT. Although increasing age was related to increased cyst prevalence, the clinical impact of cyst formation was not found to be significant at short-term follow-up. Continued long-term longitudinal follow-up of postoperative cysts is needed. LEVEL OF EVIDENCE:Level IV, prognostic case series.

Chronic lateral ankle instability can occur in a subset of patients following ankle inversion sprains. Operative treatment to restore stability in the ankle and hindfoot and to prevent further degenerative changes may be indicated in cases in which nonoperative treatment has failed. Anatomical direct repair with use of native ligament remnants with or without reinforcement of the inferior retinaculum is the so-called gold standard operative strategy for the treatment of lateral ankle instability. The procedure has shown promising short and long-term outcomes. Candidates for the procedure have ligament remnants of sufficient quality that are amendable to direct repair. Anatomical reconstruction with use of autograft or allograft is reserved for patients with insufficient ligament remnants to fashion a direct repair, failed previous lateral ankle repair, high body mass index, or generalized ligamentous laxity. A wide variety of autografts have been described, each with potential advantages and disadvantages. These procedures can provide good-to-excellent short-term outcomes. However, there is no available information on their long-term clinical results. Non-anatomical lateral ligament reconstruction typically involves the use of the adjacent peroneal brevis tendon and has been applied in cases in which only poor-quality ligament remains. The procedure can provide good to excellent short-term outcomes, although reported long-term outcomes have differed among studies. The particular tendon used for the graft should be carefully considered given the potential alterations in the kinematics of the ankle and hindfoot. Arthroscopic ligament repair is becoming increasingly popular as it is minimally invasive. This procedure is restricted to patients who have good-quality ligament remnants. Good-to-excellent clinical outcomes have been reported after short and long-term follow-up, although a relatively high rate of complications-including nerve damage-has been reported following the procedure and therefore warrants further investigation before widespread adoption can be advocated.

Talar osteochondral lesions (OCL) frequently occur following injury. Surgical interventions such as femoral condyle allogeneic or autogenic osteochondral transplant (AOT) are often used to treat large talar OCL. Although AOT aims to achieve OCL repair by replacing damaged cartilage with mechanically matched cartilage, the spatially inhomogeneous material behavior of the talar dome and femoral donor sites have not been evaluated or compared. The objective of this study was to characterize the depth-dependent shear properties and friction behavior of human talar and donor-site femoral cartilage. To achieve this objective, depth-dependent shear modulus, depth-dependent energy dissipation and coefficient of friction were measured on osteochondral cores from the femur and talus. Differences between anatomical regions were pronounced near the articular surface, where the femur was softer, dissipated more energy and had a lower coefficient of friction than the talus. Conversely, shear modulus near the osteochondral interface was nearly indistinguishable between anatomical regions. Differences in energy dissipation, shear moduli and friction coefficients have implications for graft survival and host cartilage wear. When the biomechanical variation is combined with known biological variation, these data suggest the use of caution in transplanting cartilage from the femur to the talus. Where alternatives exist in the form of talar allograft, donor-recipient mechanical mismatch can be greatly reduced.

Posterior ankle impingement syndrome (PAIS) is a common injury in athletes engaging in repetitive plantarflexion, particularly ballet dancers and soccer players. Despite the increase in popularity of the posterior two-portal hindfoot approach, concerns with the technique remain, including; the technical difficulty, relatively steep learning curve, and difficulty performing simultaneous anterior ankle arthroscopy. The purpose of the current literature review is to provide comprehensive knowledge about PAIS, and to describe a systematic four-stage approach of the posterior two-portal arthroscopy. The etiology, clinical presentation, diagnostic strategies are first introduced followed by options in conservative and surgical management. A detailed systematic approach to posterior hindfoot arthroscopy is then described. This technique allows for systematic review of the anatomic structures and treatment of the bony and/or soft tissue lesions in four regions of interest in the hindfoot (superolateral, superomedial, inferomedial, and inferolateral). The review then discusses biological adjuncts and postoperative rehabilitation and ends with a discussion on the most recent clinical outcomes after posterior hindfoot arthroscopy for PAIS. Although clinical evidence suggests high success rates following posterior hindfoot arthroscopy in the short- and mid-term it may be limited in the pathology that can be addressed due to the technical skills required, but the systematic four-stage approach of the posterior two-portal arthroscopy may improve upon this problem.

We conducted a wide-ranging review of the literature regarding osteochondral lesions of the ankle, with the aim of presenting the current concepts, treatment options, trends and future perspectives relating to this topic.

Platelet-rich plasma (PRP) and concentrated bone marrow aspirate (CBMA) have the potential to improve the quality of cartilage repair in osteochondral lesions of the talus (OLT). In this review, we describe the basic science and clinical evidence that has been published on the topic of PRP and CBMA on 2 commonly used surgical techniques for the treatment of OLT: bone marrow stimulation and osteochondral autograft transfer.

Ankle arthrodesis is a common treatment used for patients with end-stage ankle arthritis (ESAA). The surgical goal of ankle arthrodesis is to obtain bony union between the tibia and talus with adequate alignment [slight valgus (0°-5°)], neutral dorsiflexion, and slight external rotation positions) in order to provide a pain-free plantigrade foot for weightbearing activities. There are many variations in operative technique including deferring approaches (open or arthroscopic) and differing fixation methods (internal or external fixation). Each technique has its advantage and disadvantages. Success of ankle arthrodesis can be dependent on several factors, including patient selection, surgeons' skills, patient comorbidities, operative care, etc. However, from our experience, the majority of ESAA patients obtain successful clinical outcomes. This review aims to outline the indications and goals of arthrodesis for treatment of ESAA and discuss both open and arthroscopic ankle arthrodesis. A systematic step by step operative technique guide is presented for both the arthroscopic and open approaches including a postoperative protocol. We review the current evidence supporting each approach. The review finishes with a report of the most recent evidence of outcomes after both approaches and concerns regarding the development of hindfoot arthritis.