Current and Emerging Techniques in Articular Cartilage Repair.

Osteochondral lesions (OCL) of the knee are a common pathology that can be challenging to address. Due to the innate characteristics of articular cartilage, OCLs generally do not heal in adults and often progress to involve the subchondral bone, ultimately resulting in the development of osteoarthritis. The goal of articular cartilage repair is to provide a long-lasting repair that replicates the biological and mechanical properties of articular cartilage, but there is no widely adopted technique that results in true pre-injury state hyaline cartilage. Current treatment modalities have seen reasonable clinical success, but significant limitations remain. Microfracture provides short-term benefit with a fibrocartilage-based repair. While osteochondral autograft or allograft and autologous chondrocyte implantation can be effective, each have their strengths and shortcomings. Emerging concepts in cartilage repair, including scaffold engineering and one stage cell-based options, are continually advancing. These have the benefits of reduced surgical morbidity and potentially improved integration with surrounding articular cartilage but have not yet reached widespread clinical application. Tissue engineering strategies and gene therapy have the potential to advance the field, however, they remain in the early stages. The current article reviews the structure and physiology of articular cartilage, the strengths and limitations of present treatment modalities, and the newer ongoing innovations that may change the way we approach osteochondral lesions and osteoarthritis.

Patient-reported hip pain and function are worse among elite Nordic ski athletes competing in ski jumping versus Nordic combined: a cross-sectional analysis.

OBJECTIVES: Nordic ski athletes are at increased risk of developing hip pain and dysfunction secondary to femoroacetabular impingement syndrome (FAIS), but it is unclear whether hip symptomatology differs between ski jumping (SJ) and Nordic combined (NC) athletes. The purpose of this study was to compare patient-reported hip pain and dysfunction between elite Nordic ski athletes participating in SJ versus NC. METHODS: A cross-sectional study was conducted involving SJ and NC athletes who competed at the international and U.S. national levels during the 2021-2022 season. Subjects were excluded if they had hip surgery within two years prior to enrollment. Subjects were asked to undergo diagnostic workups for FAIS, including physical examination and plain radiographic imaging. Subjects were asked to complete a survey that collected information on athletic and training history and to complete the hip disability and osteoarthritis outcome score (HOOS). Demographics, athletic/training history, and HOOS sub-scores were compared between the SJ and NC groups using the Student's t-test, Wilcoxon rank-sum test, or Fisher's exact test, as appropriate. p-values < 0.05 were considered significant. RESULTS: Twenty-four athletes (13 SJ, 11 NC) were included in the study. There were no statistically significant differences in age, sex, BMI, or age of menarche between the two groups (all p â€‹> â€‹0.05). There were also no statistically significant differences in the number of prior sports participated in, total hours of participation in prior sports, or total hours of training in Nordic specialization (all p â€‹> â€‹0.05). Among the 18 athletes who underwent physical examination (9 SJ, 9 NC), there were no statistically significant inter-group differences in hip range of motion or incidence of positive impingement tests (all p â€‹> â€‹0.05). Among the 19 athletes who underwent imaging (9 SJ, 10 NC), there were no statistically significant inter-group differences in the incidence of cam or pincer morphology in at least one hip (all p â€‹> â€‹0.05). SJ athletes had statistically significantly worse HOOS sub-scores for hip symptoms and stiffness, hip function in sports/recreational activities, and hip-related quality of life compared to NC athletes (all p â€‹< â€‹0.05). CONCLUSION: Elite SJ athletes have worse self-reported hip function compared to elite NC athletes, despite comparable demographics, athletic history, and duration of ski training. LEVEL OF EVIDENCE: IV.

The Use of Computer Navigation and Robotic Technology in Complex Total Hip Arthroplasty.

Computer assisted surgical (CAS) navigation and robotic-assisted total hip arthroplasty (THA) have the potential to improve the reproducibility of accurate component positioning and facilitate complex cases, including revision and preoperative deformity. Numerous studies, including multiple comparing technology with conventional THA control groups, suggest that CAS navigation may improve component accuracy in cases of deformity such as hip dysplasia and significant leg length discrepancy. Revision THA data is also encouraging but limited. The functional benefits compared to conventional techniques remain unclear. The evidence for robot-assisted THA in complex cases is more limited but also demonstrates utility. For complex cases, studies comparing results with conventional THA are not yet available. The limitations of these systems, including cost, operative time, learning curves, and possible complications, require further study. The available data for CAS navigation and robotic-assisted THA indicates that they may play a role in complex deformity and revision cases. Further high-quality randomized studies should be undertaken.

Augmented baseplates yield optimum outcomes when compared with bone graft augmentation for managing glenoid deformity during reverse total shoulder arthroplasty: a retrospective comparative study.

PURPOSE: The purpose of this study was to compare the outcomes of primary reverse total shoulder arthroplasty (rTSA) using glenoid bone grafting (BG rTSA) with primary rTSA using augmented glenoid baseplates (Aug rTSA) with a minimum 2-year follow-up. METHODS: A total of 520 primary rTSA patients treated with 8° posterior glenoid augments (n = 246), 10° superior glenoid augments (n = 97), or combined 10° superior/8° posterior glenoid augments (n = 177) were compared with 47 patients undergoing glenoid bone grafting for glenoid bone insufficiency. The mean follow-up was 37.0(±16) and 53.0(±27) months, respectively. Outcomes were analyzed preoperatively and at the latest follow-up using conventional statistics and stratification by minimum clinically important difference (MCID) and substantial clinical benefit (SCB) thresholds where applicable. Radiographs were analyzed for baseplate failure, and the incidences of postoperative complications and revisions were recorded. RESULTS: The glenoid Aug rTSA cohort had greater improvements in patient-reported outcome measures (PROMs) and range of motion when compared with the BG rTSA group at a minimum of 2-year follow-up, including Simple Shoulder Test, Constant score, American Shoulder and Elbow Surgeons score, University of California Los Angeles score, Shoulder Pain and Disability Index score, shoulder function, Shoulder Arthroplasty Smart score, abduction, and external rotation (P < .05). Patient satisfaction was higher in the Aug rTSA group compared with the BG rTSA group (P = .006). The utilization of an augmented glenoid component instead of glenoid bone grafting resulted in approximately 50% less total intraoperative time (P < .001), nearly 33% less intraoperative blood loss volume (P < .001), approximately 3-fold less scapular notching (P < .01), and approximately 8-fold less adverse events requiring revision (P < .01) when compared with the BG rTSA cohort. Aside from SCB for abduction, the Aug rTSA cohort achieved higher rates of exceeding MCID and SCB for every PROM compared with BG rTSA. More specifically, 77.6% and 70.2% of the Aug rTSA achieved SCB for American Shoulder and Elbow Surgeons and Shoulder Pain and Disability Index vs. 55% and 48.6% in the BG rTSA, respectively (P = .003 and P = .013). CONCLUSION: The present midterm clinical and radiographic study demonstrates that the utilization of an augmented baseplate for insufficient glenoid bone stock is superior as judged by multiple PROMs and range of motion metrics when compared with bone graft augmentation at minimum 2-year follow-up. In addition, when analyzed according to MCID and SCB thresholds, the use of augmented baseplates outperforms the use of glenoid bone grafting. Complication and revision rates also favor the use of augmented glenoid baseplates over glenoid bone grafting. Long-term clinical and radiographic follow-up is necessary to confirm that these promising midterm results are durable.

Characterization of pincer-type Hip impingement in professional women's ice hockey players.

OBJECTIVE: Femoroacetabular impingement (FAI) appears common in ice hockey, but there is a lack of data examining pincer-type impingement in women's ice hockey athletes. The objective of this study was to assess the prevalence of pincer-type impingement in National Women's Hockey League (NWHL) athletes. Our hypothesis was that there would be an increased prevalence of pincer impingement in these athletes. METHODS: Data were gathered for a team of NWHL players, and age, gender, and body mass index (BMI) matched controls were also retrospectively collected. All subjects were above 18 years of age. Control patients were excluded if they had undergone prior hip surgery, were greater than age 30, or had BMI greater than 35. Radiographs of both groups were assessed for lateral center edge angle (LCEA), Tönnis angle, and crossover sign. Tönnis angle <0 or LCEA >40 degrees was considered pincer morphology. An alpha angle >55 degrees was considered cam morphology. RESULTS: Thirty-seven NWHL players and 37 female controls were included. Overall 32% of the players had a pincer lesion in either hip based on LCEA, 8% had a Tönnis angle <0, and 22% had a crossover sign in either hip compared to 9%, 19%, and 13% for the controls, respectively. None of these findings were significantly different between the groups (p > 0.05). An alpha angle ≥55 degrees in either hip was found in 84% of players, but lateral Dunn images for alpha angle measurements were not available for the control group. CONCLUSIONS: Pincer-type morphology and crossover signs were present in a larger portion of NWHL players than has been reported in the general population, but these findings were not statistically different than in the control group. Cam-type morphology was even more prevalent in these athletes and may be related to age at menarche due impingement at the physis prior to closure.

Characterizing femoroacetabular impingement in professional Nordic Skiers.

OBJECTIVE: Studies have shown a high prevalence of femoroacetabular impingement (FAI) among elite athletes yet there is a paucity of data on FAI in Nordic skiers. The purpose of this study was to determine the prevalence of radiographic FAI in professional Nordic Combined Skiers and Ski jumpers compared to controls and assess functional outcomes including hip range of motion (ROM) and pain in patients with radiographic evidence of FAI compared to those without it. METHODS: A cohort of elite Nordic Skiers underwent medical history, physical examination, and pelvic radiographs at their visit with a fellowship-trained sports medicine physician. On pelvis radiographs, Alpha angle>55 degrees was deemed cam-positive, and positive crossover signs, Tönnis<0, or LCEA>40 were deemed pincer positive. Further stratification was performed by sex, ski event type, hip pain, presence of cam lesions, and presence of pincer lesions. Spearman correlation matrix was performed to measure the association between radiographic measurements and ROM. RESULTS: Nineteen Nordic skiers and nineteen age, sex, and BMI matched controls were included in the study. There were no significant differences in age, sex, BMI, and hip pain between groups. While Nordic skiers demonstrated decreased ROM bilaterally on external rotation compared to controls, skiers had larger ROM bilaterally on extension, abduction, adduction compared to controls. Skiers were significantly more likely to have bilateral crossover sign and alpha angles>55 compared to controls. Subgroup analysis showed that Cam positive patients had higher flexion and adduction ROM and pincer positive patients had significantly higher flexion and abduction ROM compared to patients without cam and pincer lesions respectively. Patients with hip pain had significantly lower right hip abduction ROM compared to patients without hip pain. No significant correlations were seen between radiographic measurements and ROM. CONCLUSION: Similar to other elite 'hip heavy' sport athletes, Nordic skiers gave a notably higher prevalence of radiographic cam and pincer type morphology and significantly higher ROM compared to nonathletic controls. Clinicians evaluating Nordic skiers should be aware of these baseline findings with respect to a possible elevated long-term risk of symptomatic FAI in these athletes as well as other conditions related to radiographic FAI.

The effect of specialization and level of competition on injury in elite male ice hockey players.

OBJECTIVE: Young players experience pressure to focus on ice hockey at the exclusion of other sports in order to improve chances of success. Early specialization in other sports has been associated with increased injury without the benefit of improved success. The objective of the current study was to investigate whether earlier specialization results in increased injury without higher rates of career success. This study also aimed to compare rates of injury in athletes at various levels of competition. METHODS: An original survey was issued to men's ice hockey players at the juniorA, collegiate, and professional levels. The survey consisted of 34 questions on various demographic, specialization, and injury variables. All participants were >18 years of age. RESULTS: The survey was completed by 101 athletes. The mean age at specialization was 13 (±4) overall and 14 (±3), 13 (±4), and 11(±4) for professional, collegiate, and junior players, respectively. There was no difference in age at specialization between each group and professional players did not specialize earlier than the remainder of the cohort as a whole (p > 0.05). There was no significant correlation between age at specialization and total injuries (p > 0.05). There was no difference in concussions causing missed play time between groups (p > 0.05) but professional players had more overall concussions and underwent more surgeries due to hockey-related injuries (p = 0.01). CONCLUSIONS: Specializing exclusively in ice hockey earlier in life was not associated with playing professionally. Both collegiate and professional players do not tend to specialize prior to age 12. Age at specialization was not associated with overall number of injuries. Professional players with longer careers appear to sustain more concussions and undergo more surgery.

The Use of Computer Navigation and Robotic Technology in Complex Total Knee Arthroplasty.

¼: The potential benefits of computer-assisted surgical (CAS) navigation and robotic total knee arthroplasty (TKA) systems, such as increased reliability of restoring the mechanical axis, fewer outliers, more rapid hospital discharge, less physical therapy requirements, decreased blood loss, and decreased revision rates, have led to their application not only in primary cases but also in complex cases such as preoperative deformity and revision. ¼: Early evidence demonstrates that CAS navigation may help to improve alignment in complex cases of femoral and tibial deformity and in cases of femoral bowing. ¼: Data regarding deformity correction with robotic systems are similar to CAS navigation with regard to alignment, but are more limited. There are also scant data regarding revision cases and cases of previous intramedullary canal instrumentation. ¼: Concerns remain regarding cost, learning curves, and operative times. There are potential long-term cost savings associated with a decrease in revisions and readmissions that require additional investigation. ¼: Early evidence for the use of these emerging technologies for deformity correction and revision cases is promising, but their impact on long-term functional outcomes remains to be demonstrated. Additional well-designed comparative studies are warranted.

NURD 2.0: Prediction of tibial nonunion after intramedullary nail fixation at any time within 3 months after injury.

Introduction Nonunion after fixation of long bones negatively impacts outcomes and requires additional surgery. The ability to predict likelihood of nonunion after tibial shaft fracture would be helpful to clinicians and patients. The goal of this work was to combine three previous models of tibial shaft nonunion at different time points into one overall model that incorporates time as a continuous variable. Methods We conducted a retrospective review at a Level I academic trauma center. The study cohort consisted of patients with tibial shaft fractures treated with nail insertion from 2007 through 2014, excluding patients who did not have contact between bone ends, those who had planned bone grafting for acute bone defects, and those who lacked adequate follow-up. Three previous models were combined: 382 patients at time 0, 323 at 6 weeks, and 240 at 12 weeks. The primary outcome variable was surgery for nonunion. Bivariate and multivariate regression analyses determined which of 42 clinical and radiographic variables were significantly associated with nonunion. Predictive power was evaluated using area under the curve (AUC). Results The original nonunion risk determination (NURD) score was significantly improved through addition of 6- and 12-week radiographic union scores for tibial fractures, infection and complications, smoking status, and need for flaps. Overall, over the course of 12 weeks, the NURD-based model produced an AUC of 0.87 at initial time of fixation that improved to >0.9 at 6 and 12 weeks. Data were used to bin patients into five clinically important risk strata (p < 0.001). Patients in the lowest risk strata had 0% probability of nonunion (0 of 97 patients); in the second lowest risk strata, 4% (three of 73 patients); and in the highest risk strata, 48% (38 of 80 patients). Conclusions We created a NURD 2.0 score that predicts nonunion at various time points during the first 3 months after fracture. The new model is a notable improvement over previous models. A computerized version allows surgeons and patients to use the score when making treatment decisions regarding need for nonunion surgery.

Hartmann's Pouch Stones and Laparoscopic Cholecystectomy: The Challenges and the Solutions.

BACKGROUND & OBJECTIVE: Hartmann's pouch stones (HPS) encountered during laparoscopic cholecystectomy (LC) may hinder safe dissection of the cystic pedicle or be complicated by mucocele, empyema, or Mirizzi syndrome; distorting the anatomy and increasing the risk of bile duct injury. We studied the incidence, presentations, operative challenges, and outcomes of HPS. METHODS: A cohort study of a prospectively maintained database of LCs and bile duct explorations performed by a single surgeon. Patients were divided into two groups: those with HPS and those without. Patients' demographics, clinical presentation, intra-operative findings, and postoperative outcomes were compared. RESULTS: Of the 5136 patients, 612 (11.9%) had HPS. The HPS group were more likely to present with acute cholecystitis (27.9% vs 5.9%, P = .000) and more patients underwent emergency LC (50.7% vs 41.5%, P = .000). The HPS group had more difficult cholecystectomies, with 46.1% vs 11.8% in the non-HPS group being operative difficulty grade 4 and 5. Mucocele, empyema, and Mirizzi syndrome were more common in the HPS group (24.0% vs 3.7% P = .000, 30.9% vs 3.7% P = .000, 1.8% vs 0.9% P = .000, respectively). There was no significant difference in the open conversion rate or complications. CONCLUSION: HPS increase the difficulty of LC. Surgeons should be aware of their presence and should employ appropriate dissection strategies. Sharp or diathermy dissection should be avoided. Dislodging the stone into the gall bladder, stone removal, swab dissection, and cholangiography are useful measures to avoid ductal injury and reduce the conversion rate.

Lesion Size Measured on MRI Does Not Accurately Reflect Arthroscopic Measurement in Talar Osteochondral Lesions.

BACKGROUND: Lesion size is a major determinant of treatment strategy for osteochondral lesions of the talus (OLTs). Although magnetic resonance imaging (MRI) is commonly used in the preoperative evaluation of OLTs, the reliability of the MRI measurement compared with the arthroscopic measurement is unknown. PURPOSE: To compare preoperative lesion size measured on MRI versus intraoperative lesion size measured during arthroscopy. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: We retrospectively reviewed a consecutive series of patients treated with bone marrow stimulation for OLTs. The diameter of the lesion was measured at its widest point in 2 planes, and MRI measurements were compared with those made during arthroscopy using a custom-made graduated probe. RESULTS: A total of 39 patients with 45 OLTs were analyzed. Mean ± SD area measurements on MRI were significantly greater than the equivalent arthroscopic measurements (42.2 ± 30.5 vs 28.6 ± 23.1 mm2, respectively; P = .03). Compared with the arthroscopic measurement, MRI overestimated OLT size in 53.3% (24/45) of ankles and underestimated OLT size in 24.4% (11/45). The mean MRI diameter measurement was significantly greater than the arthroscopic measurement in the coronal plane (MRI diameter vs arthroscopic measurement coronal plane, 6.1 ± 2.6 vs 4.9 ± 2.3 mm, P = .03; sagittal plane, 8.0 ± 3.6 vs 6.3 ± 3.6 mm, P = .05). Further, MRI overestimated coronal diameter in 48.9% (22/45) of ankles and underestimated in 26.7% (12/45) compared with the arthroscopic measurement. Similarly, sagittal plane MRI diameter measurements overestimated lesion size in 46.7% (21/45) of ankles and underestimated lesion size in 28.9% (13/45) compared with the arthroscopic findings. CONCLUSION: In a majority of lesions, MRI overestimated OLT area and diameter compared with arthroscopy. Surgeons should be aware of the discrepancies that can exist between MRI and arthroscopic measurements, as these data are important in making treatment decisions and educating patients.

Prediction of tibial nonunion at the 6-week time point.

INTRODUCTION: Intramedullary (IM) nail fixation is a common operative treatment, yet concerns regarding the frequency of complications, such as nonunion, remain. Treatment of tibial shaft fractures remains a challenge, and little evidence of prognostic factors that increase risk of nonunion is available. The aim of this study was to develop a predictive model of tibial shaft fracture nonunion 6 weeks after reamed intramedullary (IM) nail fixation based on commonly collected clinical variables and the radiographic union score for tibial fractures (RUST). METHODS: A retrospective case-control study was conducted. All tibial shaft fractures treated at our level I trauma center from 2007 to 2014 were retrospectively reviewed. Only patients with follow-up until fracture healing or secondary operation for nonunion were included. Fracture gaps ≥3 mm were excluded. A total of 323 patients were included for study. RESULTS: Infection within 6 weeks of operation, standard RUST, and the Nonunion Risk Determination (NURD) score had statistically significant associations with nonunion (odds ratio > or < 1.0; p < 0.01). The NURD score was increasingly predictive of nonunion with decreasing RUST. All patients in the high RUST group (RUST ≥ 10), achieved union regardless of NURD score. In the medium RUST group (RUST 6-9), 25% of patients with a NURD score ≥7 experienced nonunion. In the low RUST group (RUST <6 or infection within 6 weeks), 69% of patients with a NURD score ≥7 experienced nonunion. CONCLUSION: Three variables predicted nonunion. Based on these variables, we created a clinical prediction tool of nonunion that could aid in clinical decision making and discussing prognosis with patients.

Bone marrow concentrate and platelet-rich plasma differ in cell distribution and interleukin 1 receptor antagonist protein concentration.

PURPOSE: Bone marrow concentrate (BMC) and platelet-rich plasma (PRP) are used extensively in regenerative medicine. The aim of this study was to determine differences in the cellular composition and cytokine concentrations of BMC and PRP and to compare two commercial BMC systems in the same patient cohort. METHODS: Patients (29) undergoing orthopaedic surgery were enrolled. Bone marrow aspirate (BMA) was processed to generate BMC from two commercial systems (BMC-A and BMC-B). Blood was obtained to make PRP utilizing the same system as BMC-A. Bone marrow-derived samples were cultured to measure colony-forming units, and flow cytometry was performed to assess mesenchymal stem cell (MSC) markers. Cellular concentrations were assessed for all samples. Catabolic cytokines and growth factors important for cartilage repair were measured using multiplex ELISA. RESULTS: Colony-forming units were increased in both BMCs compared to BMA (p < 0.0001). Surface markers were consistent with MSCs. Platelet counts were not significantly different between BMC-A and PRP, but there were differences in leucocyte concentrations. TGF-ß1 and PDGF were not different between BMC-A and PRP. IL-1ra concentrations were greater (p = 0.0018) in BMC-A samples (13,432 pg/mL) than in PRP (588 pg/mL). The IL-1ra/IL-1ß ratio in all BMC samples was above the value reported to inhibit IL-1ß. CONCLUSIONS: The bioactive factors examined in this study have differing clinical effects on musculoskeletal tissue. Differences in the cellular and cytokine composition between PRP and BMC and between BMC systems should be taken into consideration by the clinician when choosing a biologic for therapeutic application. LEVEL OF EVIDENCE: Clinical, Level II.

Platelet-Rich Plasma and Hyaluronic Acid Are Not Synergistic When Used as Biological Adjuncts with Autologous Osteochondral Transplantation.

Introduction Autologous osteochondral transplantation (AOT) is a treatment for osteochondral lesions with known concerns, including histological degradation of the graft and poor cartilage integration. Platelet-rich plasma (PRP) and hyaluronic acid (HA) have been described has having the potential to improve results. The aim of this study was to evaluate the effect of PRP and HA on AOT in a rabbit model. Methods Thirty-six rabbits underwent bilateral knee AOT treated with either the biological adjunct (PRP, n = 12; HA, n = 12; PRP + HA, n = 12) or saline (control). PRP and HA were administered as an intra-articular injection. The rabbits were euthanized at 3, 6, or 12 weeks postoperatively. The graft sections were assessed using the modified International Cartilage Repair Society (ICRS) scoring system. The results from the PRP alone group is from previously published data. Results The mean modified ICRS histological score for the PRP-treated group was higher than its control ( P = 0.002). The mean modified ICRS histological score for the HA-treated group showed no difference compared with its control ( P = 0.142). The mean modified ICRS histological score for the PRP + HA-treated group was higher than its control ( P = 0.006). There was no difference between the mean modified ICRS scores of the PRP- and the PRP + HA-treated grafts ( P = 0.445). Conclusion PRP may decrease graft degradation and improve chondral integration in an animal model. In this model, the addition of HA was not synergistic for the parameters assessed. LEVEL OF EVIDENCE: Basic science, Level V. CLINICAL RELEVANCE: PRP can be used as an adjunct to AOT, which may decrease graft degeneration and improve clinical outcomes. HA may not influence AOT.

Current concepts review: Arthroscopic treatment of anterior ankle impingement.

Anterior ankle impingement is a common cause of chronic ankle pain, particularly in athletic populations. Morris and McMurray provided the earliest descriptions of anterior impingement, coining the condition as "athlete's ankle" or "footballer's ankle". The pathology has since been a topic of considerable investigation and has been re-termed "anterior ankle impingement syndrome". Treatment with open surgery has provided good results historically, but at the price of significant complications. Advancements in ankle arthroscopy have decreased the risk of complication drastically and evidence in the literature indicates that anterior arthroscopy is an effective approach to treating osseous and soft tissue impingement. Effective clinical diagnosis and diagnostic imaging are critical for pre-surgical planning. Preoperative detection of anterior osteophytes has been correlated with outcomes. Factors such as joint space narrowing and large osteophytes may also influence outcomes. Therefore, a comprehensive understanding of diagnosis and surgical technique can influence patient outcomes, and patient expectations can be managed around prognostic indicators such as the presence of osteoarthritis. The purpose of this review is to discuss the etiology, clinical presentation, diagnosis, surgical technique, and postoperative rehabilitation of anteromedial and anterolateral anterior ankle impingement syndrome and to evaluate the evidence-based outcomes of arthroscopic management.

Human talar and femoral cartilage have distinct mechanical properties near the articular surface.

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.

Magnetic Resonance Imaging Evidence of Postoperative Cyst Formation Does Not Appear to Affect Clinical Outcomes After Autologous Osteochondral Transplantation of the Talus.

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.

Clinical and MRI Donor Site Outcomes Following Autologous Osteochondral Transplantation for Talar Osteochondral Lesions.

BACKGROUND: Autologous osteochondral transplantation (AOT) has an inherent risk of donor site morbidity (DSM). The reported rates of DSM vary from 0% to 50%, with few studies reporting clinical or imaging outcomes at the donor site as a primary outcome and even fewer report these outcomes when a biosynthetic plug backfill is employed. Although TruFit (Smith & Nephew, Andover, MA) plugs have been removed from the market for regulatory purposes, biphasic plugs (including TruFit plugs) have been used for several years and the evaluation of these is therefore pertinent. METHODS: Thirty-nine patients who underwent forty AOT procedures of the talus, with the donor graft being taken from the ipsilateral knee, were included. Postoperative magnetic resonance imaging (MRI) was used to assess the donor site graded with magnetic resonance observation of cartilage repair tissue (MOCART) scoring. Lysholm scores were collected preoperatively, at the time of magnetic resonance imaging (MRI), and again at 24 months and at final follow-up to assess clinical outcomes. Statistical analysis was performed to establish if there was any correlation between MRI assessment of the donor site and clinical outcomes. The mean patient age was 36.2 ± 15.7 years with a mean follow-up of 41.8 ± 16.7 months. RESULTS: All patient donor site defects were filled with OBI TruFit biphasic plugs. DSM was encountered in 12.5% of the patient cohort at 24 months, and in these patients, the Lysholm score was a mean 87.2 ± 5.0. At final follow-up, DSM was reduced to 5%. Lysholm scores for the entire cohort were 98.4 ± 4.6 and 99.4 ± 3.1 at 24 months and final follow-up, respectively. MRI of the donor sites were taken at an average of 18.1 ± 13.5 (range, 3-48) months postoperatively and the mean MOCART score was 60.0 ± 13.5. No correlation was found between the MOCART score and Lysholm outcomes at the donor knee (P = .43, r = 0.13). CONCLUSION: Low incidence of DSM and good functional outcomes were achieved with AOT. Additionally, MRI findings did not predict clinical outcomes in our study. LEVEL OF EVIDENCE: Level IV, retrospective case series.

The Effect of Different Bone Marrow Stimulation Techniques on Human Talar Subchondral Bone: A Micro-Computed Tomography Evaluation.

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.

Autologous Osteochondral Transplantation for Osteochondral Lesions of the Talus: Does Previous Bone Marrow Stimulation Negatively Affect Clinical Outcome?

PURPOSE: To determine if functional outcomes and magnetic resonance imaging (MRI) outcomes were significantly different between patients receiving primary autologous osteochondral transplantation (AOT) and patients receiving secondary AOT surgery after failed microfracture. METHODS: A group of 76 patients enrolled into the Foot and Ankle Service between 2006 and 2012 was retrospectively analyzed. Patient-reported outcomes were evaluated in 76 patients using the Foot and Ankle Outcome Score (FAOS). Superficial and deep tissues at the repaired defect site, as well as the adjacent normal cartilage, were analyzed using quantitative T2 mapping MRI. Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) allowed for morphological evaluation of the repair tissue. The mean clinical follow-up time was 51 ± 23 months (range, 12 to 97 months), and the mean MRI follow-up time was 26 months (range, 24 to 36 months). RESULTS: Twenty-two patients received primary AOT and 54 received secondary AOT after failed microfracture. Patient characteristics between groups were similar with regard to age, gender, lesion size, and follow-up time. The mean postoperative FAOS was 10 points higher in the primary AOT group (83.2 ± 17.0) compared with the secondary AOT group (72.4 ± 19.4) (P = .01). Regression analysis showed that secondary AOT patients preoperative to postoperative change in FAOS was 9 points lower than in primary AOT patients after adjustment for age, preoperative FAOS, and lesion size (P = .045). The mean MOCART score, superficial T2 and deep T2 values, and the difference between normal and repair cartilage T2 values were not significantly different between groups. Lesion size was negatively correlated with MOCART scores (ρ = -0.2, P = .04), but positively correlated with difference in T2 values between repair and adjacent normal cartilage in the superficial layer (ρ = 0.3, P = .045). CONCLUSIONS: Primary AOT shows better functional outcomes compared with secondary AOT after failed microfracture in patients with similar characteristics and lesion size. No significant differences in T2 mapping relaxation times and MOCART scores were identified. LEVEL OF EVIDENCE: Level III, case control study.