Postoperative complications of posterior ankle and hindfoot arthroscopy

BACKGROUND

Posterior ankle and hindfoot arthroscopy, performed with use of posteromedial and posterolateral portals with the patient in the prone position, has been utilized for the treatment of various disorders. However, there is limited literature addressing the postoperative complications of this procedure. In this study, the postoperative complications in patients treated with posterior ankle and hindfoot arthroscopy were analyzed to determine the type, rate, and severity of complications.

METHODS

The study included 189 ankles in 186 patients (eighty-two male and 104 female; mean age, 37.1 ± 16.4 years). The minimum duration of follow-up was six months, and the mean was 17 ± 13 months. The most common preoperative intra-articular diagnoses were subtalar osteoarthritis (forty-six ankles), an osteochondral lesion of the talus (forty-two), posterior ankle impingement (thirty-four), ankle osteoarthritis (twenty), and subtalar coalition (five). The most common extra-articular diagnoses were painful os trigonum (forty-six), flexor hallucis longus tendinitis (thirty-two), and insertional Achilles tendinitis (five).

RESULTS

The most common intra-articular procedures were osteochondral lesion debridement (forty-four ankles), subtalar debridement (thirty-eight), subtalar fusion (thirty-three), ankle debridement (thirty), and partial talectomy (nine). The most common extra-articular procedures were os trigonum excision (forty-eight), tenolysis of the flexor hallucis longus tendon (thirty-eight), and endoscopic partial calcanectomy (five). Complications were noted following sixteen procedures (8.5%); four patients had plantar numbness, three had sural nerve dysesthesia, four had Achilles tendon tightness, two had complex regional pain syndrome, two had an infection, and one had a cyst at the posteromedial portal. One case of plantar numbness and one case of sural nerve dysesthesia failed to resolve.

CONCLUSIONS

Our experience demonstrated that posterior ankle and hindfoot arthroscopy can be performed with a low rate of major postoperative complications.

One-step osteochondral repair with cartilage fragments in a composite scaffold

PURPOSE

This study proposes a single-step therapeutic approach for osteochondral defects using autologous cartilage fragments loaded onto a scaffold composed of a hyaluronic acid (HA) derivative, human fibrin glue (FG) and autologous platelet-rich-plasma (PRP), in a rabbit model. The aim is to demonstrate the in vitro outgrowth of chondrocytes from cartilage fragments and the in vivo formation of a functional repair tissue.

METHODS

In vitro: minced articular cartilage was loaded onto two different types of scaffold (paste or membrane) according to two different HA preparations (injectable HA-derivative or HA-derivative felt). In vivo: trochlear osteochondral defects were created in 50 adult rabbits, which were then assigned to 5 different treatment groups: cartilage fragments loaded onto membrane scaffolds with FG (Group 1) or without FG (Group 2); membrane scaffolds alone with FG (Group 3) or without FG (Group 4); empty defects (Group 5). Membrane scaffolds were used "in vivo" for simpler preparation and better adhesive properties. Repair processes were evaluated histologically and by immunohistochemistry at 1, 3, and 6 months.

RESULTS

An in vitro time-dependent cell outgrowth from cartilage fragments was observed with both types of scaffolds. At 6 months, in vivo, cartilage fragment-loaded scaffolds induced significantly better repair tissue than the scaffold alone using histological scoring. Repair in Group 2 was superior to that in any of the control groups (p < 0.05).

CONCLUSION

Autologous cartilage fragments loaded onto an HA felt/FG/PRP-scaffold provided an efficient cell source, and allowed for an improvement of the repair process of ostechondral defects in a rabbit model. Human FG, however, hampered the rabbit healing process. These results may have clinical relevance as they show the potential of a novel one-stage repair technique for osteochondral defects.

Autologous cartilage fragments in a composite scaffold for one stage osteochondral repair in a goat model

We propose a culture-free approach to osteochondral repair with minced autologous cartilage fragments loaded onto a scaffold composed of a hyaluronic acid (HA)-derived membrane, platelet-rich fibrin matrix (PRFM) and fibrin glue. The aim of the study was to demonstrate in vitro the outgrowth of chondrocytes from cartilage fragments onto this scaffold and, in vivo, the formation of functional repair tissue in goat osteochondral defects. Two sections were considered: 1) in vitro: minced articular cartilage from goat stifle joints was loaded onto scaffolds, cultured for 1 or 2 months, and then evaluated histologically and immunohistochemically; 2) in vivo: 2 unilateral critically-sized trochlear osteochondral defects were created in 15 adult goats; defects were treated with cartilage fragments embedded in the scaffold (Group 1), with the scaffold alone (Group 2), or untreated (Group 3). Repair processes were evaluated morphologically, histologically, immunohistochemically and biomechanically at 1, 3, 6 and 12 months. We found that in vitro, chondrocytes from cartilage fragments migrated to the scaffold and, at 2 months, matrix positive for collagen type II was observed in the constructs. In vivo, morphological and histological assessment demonstrated that cartilage fragment-loaded scaffolds led to the formation of functional hyaline-like repair tissue. Repair in Group 1 was superior to that of control groups, both histologically and mechanically. Autologous cartilage fragments loaded onto an HA/PRFM/fibrin glue scaffold provided a viable cell source and allowed for an improvement of the repair process of osteochondral defects in a goat model, representing an effective alternative for one-stage repair of osteochondral lesions.

Can we improve the reliability of the Constant-Murley score?

HYPOTHESIS

The Constant-Murley score (CMS) is one of the most used scales for shoulder dysfunction. The aim of this study is to determine whether the reliability of the CMS can be improved by enhancing the standardization of the items.

METHODS

Two consecutive series of 55 patients with shoulder dysfunction were enrolled in a test-retest study and examined by 2 orthopedic surgeons with different levels of expertise. The following scores were measured: CMS, individual relative CMS, relative CMS, and standardized CMS. For each variable, the intraobserver and interobserver reliability was calculated.

RESULTS

The less experienced observer had worse intraobserver reliability using the CMS (error, 4 points; 95% limit of agreement, 22) than the expert observer (error, 2.4 points; 95% limit of agreement, 16). The standardized CMS showed better intraobserver reliability, with an error of 0.4 points and 95% limits of agreement of 9 for the expert observer and 13 for the less experienced observer. The correction against the contralateral unaffected side and the reference population determined a worsening of reliability in both observers. Interobserver reliability showed an improvement similar to that of intraobserver reliability (systematic error, 4; 95% limit of agreement, 24) by use of the CMS and improved to 1 point when the standardized CMS was adopted (95% limit of agreement, 12).

CONCLUSIONS

This study showed that the standardization of the items significantly improved both the intraobserver reliability and interobserver reliability of the CMS. The level of expertise of the observer has less of an effect on reliability when the score is applied with a higher level of standardization.

Human cartilage fragments in a composite scaffold for single-stage cartilage repair: an in vitro study of the chondrocyte migration and the influence of TGF-β1 and G-CSF

PURPOSE

Minced chondral fragments are becoming popular as a source of cells for cartilage repair, as a growing interest is developing towards one-stage procedures to treat cartilage lesions. The purpose of this study is to (A) compare cell outgrowth from cartilage fragments of adult and young donors using two different types of scaffolds and (B) evaluate the influence of transforming-growth-factor-β1 (TGF-β1) and granulocyte colony-stimulating factor (G-CSF) on chondrocyte behaviour.

METHODS

In part (A) cartilage fragments from adult and young donors were either loaded onto an HA-derivative injectable paste scaffold or onto an HA-derivative membrane scaffold. Construct sections were then examined for cell counting after 1, 2 and 3 months. In part (B) only membrane scaffolds were prepared using cartilage fragments from young donors. Constructs were cultured either in standard growth medium or in the presence of specific growth factors, such as TGF-β1 or G-CSF or TGF-β1 + G-CSF. After 1 month, construct sections were examined for cell counting. Expression of chondrocyte markers (SOX9, CD151, CD49c) and proliferative markers (β-catenin, PCNA) was assessed using immunofluorescence techniques, both in unstimulated construct sections and in cells from unstimulated and stimulated construct cultures.

RESULTS

Part (A): histological analysis showed age-dependent and time-dependent chondrocyte migration. A significant difference (p < 0.05) was observed between young and older donors at the same time point. No difference was detected between the two types of scaffolds within the same group at the same time point. Part (B): after 1 month, the number of migrating cells/area significantly increased due to exposure to TGF-β1 and/or G-CSF (p < 0.05). Immunofluorescence revealed that outgrowing cells from unstimulated scaffold sections were positive for SOX9, CD151, CD49c and G-CSF receptor. Immunofluorescence of cells from construct cultures showed an increase in β-catenin in all stimulated groups and an increased PCNA expression in G-CSF-exposed cultures (p < 0.05).

CONCLUSION

Outgrowing cells may represent a subset of chondrocytes undergoing a phenotypic shift towards a proliferative state. TGF-β1, and to a greater extent G-CSF, may accelerate this outgrowth. The clinical relevance of this study may involve a potential future clinical application of scaffolds preloaded with growth factors as an additional coating for chondral fragments. Indeed, a controlled delivery of G-CSF, widely employed in various clinical settings, might improve the repair process driven by minced human cartilage fragments during one-stage cartilage repair.

Large Osteochondral Allografts of the Knee: Surgical Technique and Indications

Large osteochondral allograft (OCA) transplant has become a valid alternative to restore articular surface in challenging articular lesions in young and active patients, either in primary or in revision procedures. Several studies support the effectiveness and safety of OCA, but costs and graft availability limit their use. The indications are the treatment of symptomatic full-thickness cartilage lesions greater than 3 cm ² , deep lesions with subchondral damage, or revision procedures when a previous treatment has failed. The goal of the transplant is to restore the articular surface with a biological implant, allow return to daily/sports activities, relieve symptoms, and delay knee arthroplasty. Grafts can be fresh, fresh-frozen, or cryopreserved; these different storage procedures significantly affect cell viability, immunogenicity, and duration of the storage. Dowel and shell technique are the two most commonly used procedures for OCA transplantation. While most cartilage lesions can be treated with the dowel technique, large and/or geometrically irregular lesions should be treated with the shell technique. OCA transplantation for the knee has demonstrated reliable mid- to long-term results in terms of graft survival and patient satisfaction. Best results are reported: in unipolar lesions, in patients younger than 30 years, in traumatic lesions and when the treatment is performed within 12 months from the onset of symptoms.

Factors Affecting Subjective and Objective Outcomes and Return to Play in Anterior Cruciate Ligament Reconstruction: A Retrospective Cohort Study

Purpose  To analyze the prognostic factors influencing subjective and objective outcomes and return to play (RTP) after anterior cruciate ligament reconstruction (ACL-R).

Methods  Primary ACL-Rs using a transtibial technique performed between 2008 and 2012 were included. Data regarding patients, surgery, sports, and rehabilitation, including an on-field rehabilitation (OFR) and duration of the rehabilitation program, were collected. The International Knee Documentation Committee (IKDC) subjective and objective evaluation forms, and the Knee Injury and Osteoarthritis Outcome Score and Lysholm questionnaires were used for the assessment of subjective and objective outcomes. The Subjective Patient Outcome for Return to Sports and ACL–return to sport after injury (RSI) scores were used for RTP evaluation. Several potential predictors of outcome were tested with a univariate analysis. All the variables with p  < 0.1 were retested in a logistic regression model to evaluate their association with the outcomes.

Results  In total, 176 cases were included with an average follow-up of 44.1 months. Of the patients, 92.2% were rated as normal or nearly normal at the IKDC evaluation. In addition, 90.1% of the patients returned to sport, with 57.6% returning to the same preinjury level. Objective outcomes were negatively influenced by late rehabilitation (odds ratio [OR] = 2.75). Performing an OFR phase during the rehabilitation was associated with better subjective outcomes (OR = 2.71). Length of rehabilitation strongly influenced the RTP rate (OR = 13.16). Conversely, higher ACL-RSI score was inversely related to RTP. Objective IKDC score was inversely related to the ACL-RSI (OR = 0.31), whereas subjective score was correlated with both the total ACL-RSI score (OR = 0.15) and the level of activity (OR = 0.20).

Conclusion  This study confirmed the role of rehabilitation on subjective and objective outcomes and on RTP. Particularly, the complete adherence to a rehabilitation program, including an OFR phase, resulted in better subjective outcomes and higher RTP rate. The relationship between psychological factors, measured through the ACL-RSI score, and RTP was confirmed.

Level of Evidence  Level III, observational study without a control group.

Mechanical Stimulation (Pulsed Electromagnetic Fields "PEMF" and Extracorporeal Shock Wave Therapy "ESWT") and Tendon Regeneration: A Possible Alternative

The pathogenesis of tendon degeneration and tendinopathy is still partially unclear. However, an active role of metalloproteinases (MMP), growth factors, such as vascular endothelial growth factor (VEGF) and a crucial role of inflammatory elements and cytokines was demonstrated. Mechanical stimulation may play a role in regulation of inflammation. In vitro studies demonstrated that both pulsed electromagnetic fields (PEMF) and extracorporeal shock wave therapy (ESWT) increased the expression of pro-inflammatory cytokine such as interleukin (IL-6 and IL-10). Moreover, ESWT increases the expression of growth factors, such as transforming growth factor β(TGF-β), (VEGF), and insulin-like growth factor 1 (IGF1), as well as the synthesis of collagen I fibers. These pre-clinical results, in association with several clinical studies, suggest a potential effectiveness of ESWT for tendinopathy treatment. Recently PEMF gained popularity as adjuvant for fracture healing and bone regeneration. Similarly to ESWT, the mechanical stimulation obtained using PEMFs may play a role for treatment of tendinopathy and for tendon regeneration, increasing in vitro TGF-β production, as well as scleraxis and collagen I gene expression. In this manuscript the rational of mechanical stimulations and the clinical studies on the efficacy of extracorporeal shock wave (ESW) and PEMF will be discussed. However, no clear evidence of a clinical value of ESW and PEMF has been found in literature with regards to the treatment of tendinopathy in human, so further clinical trials are needed to confirm the promising hypotheses concerning the effectiveness of ESWT and PEMF mechanical stimulation.

Clinical examination of the knee: know your tools for diagnosis of knee injuries

The clinical evaluation of the knee is a fundamental tool to correctly address diagnosis and treatment, and should never be replaced by the findings retrieved by the imaging studies carried on the patient.Every surgeon has his own series of exams with whom he is more confident and on whom he relies on for diagnosis. Usually, three sets of series are used: one for patello-femoral/extensor mechanism pathologies; one for meniscal and chondral (articular) lesions; and one for instability evaluation.This review analyses the most commonly used tests and signs for knee examination, outlining the correct way to perform the test, the correct interpretation of a positive test and the best management for evaluating an injured knee both in the acute and delayed timing.

Validity and reliability of the SPORTS score for shoulder instability

PURPOSE

athletes affected by shoulder instability cannot be judged solely according to the criteria used for non-athletes. In order to improve the assessment of shoulder instability surgery outcomes, the SPORTS score was tested in a cohort of athletes.

METHODS

ninety-eight athletes at an average follow-up of 4.6 years (range 1-9.2) after open or arthroscopic surgery for recurrent anterior shoulder instability were included in this study. The patients were asked to complete the SPORTS score questionnaire twice, with an interval of 2-3 weeks between the two assessments. The Bland-Altman method and the intra-class correlation coefficient were used to measure reliability. Criterion validity was assessed by calculating the Spearman correlation coefficient between the SPORTS score and the Western Ontario Shoulder Instability Index (WOSI) score, the Rowe score, the Oxford Shoulder Instability Score (OSIS), and the Subjective Shoulder Value (SSV).

RESULTS

the SPORTS score showed excellent test-retest reliability. The systematic error between the first and the second assessment was 0.3 points (95% upper limit of agreement = 2.3 points). The criterion validity was found to be strong for the SPORTS score, which correlated best with the SSV and the "sport, recreation, and work" component of the WOSI score. The SPORTS score had an acceptable floor effect (8%). The ceiling effect was 46%, which was better than the ceiling effects seen with the Rowe, OSIS and WOSI scores.

CONCLUSIONS

this study suggests that the SPORTS score is a valid score in the assessment of athletes after surgery for shoulder instability and that it adds important information to the currently available scores.

LEVEL OF EVIDENCE

Level III, diagnostic study of nonconsecutive patients.

Osteochondral talar allograft for large osteochondral defects: technique tip

Level of Evidence: V, Expert Opinion

Modifiable and Nonmodifiable Predictive Factors Associated with the Outcomes of Total Knee Arthroplasty

Total knee arthroplasty (TKA) is a valuable treatment option for advanced osteoarthritis in patients unresponsive to conservative treatments. Despite overall satisfactory results, the rate of unsatisfied patients after TKA remains high, ranging from 5 to 40%. Different modifiable and nonmodifiable prognostic factors associated with TKA outcomes have been described. The correction, whenever possible, of modifiable factors is fundamental in preoperative patients' optimization protocols. Nonmodifiable factors can help in predicting the outcomes and creating the right expectations in the patients undergoing TKA. The goal of this review is to summarize the modifiable and nonmodifiable prognostic factors associated with TKA outcomes.

Influence of timing and oral anticoagulant/antiplatelet therapy on outcomes of patients affected by hip fractures

BACKGROUND

Patients undergoing surgical procedures are usually asked to discontinue any anticoagulant/antiplatelet therapy and delay surgery for at least 5 days to reduce the risk of major bleeding and spinal hematoma.

AIM

The purpose of this study was to determine if this strategy is suitable for patients on anticoagulant/antiplatelet therapy affected by a hip fracture, evaluating the effect of anticoagulant/antiplatelet therapy and surgical timing on mortality and complication rates for patients affected by a hip fracture.

PATIENTS AND METHODS

We performed an observational study on patients referring to our hospital for a hip fracture. We evaluated patients on warfarin, ticlopidine, and aspirin therapy matched to patients not on anticoagulant or antiplatelet therapy, out of 875 consecutive patients treated for a hip fracture in a 5-year period. Blood loss, blood transfusions, length of hospitalization, walking ability, complications, and mortality at 1 year of follow-up were recorded. Kruskal-Wallis, Mann-Whitney U, and logistic regression statistical tests were performed.

RESULTS

Patients on warfarin therapy operated more than 5 days after admission showed significantly higher complication and mortality rates compared to all other patients. Two critical factors were identified: warfarin therapy and excessive time to surgery; these factors are not significant if taken alone, while they become a high-risk factor if taken together.

CONCLUSION

The "discontinue drug, and delay surgery" strategy is not suitable for patients on anticoagulant (warfarin) therapy affected by a hip fracture.

Epidemiology of hip fractures in northwestern Italy: a multicentric regional study on incidence of hip fractures and their outcome at 3-year follow-up

Piedmont is a region in northwestern Italy counting 4.2 million inhabitants. The purpose of our study was to update data on incidence and outcomes of hip fractures (HF) in our region to present days. The data of all patients affected by HF in 2003 in Piedmont (total: 5,386 patients) were analyzed, determining the incidence of HF, mean age, sex, fracture pattern and treatment adopted. Additionally, 564 patients underwent a questionnaire on comorbidities, complications, functional outcome and survivorship. Overall incidence of HF was 126.13/100,000 inhabitants-year. Mean hospitalization was 13.67 days. Mean time to surgery was 2.67 days. Survivorship was 94% at 3-month, 71.32% at 1-year and 60.21% at 3-year follow-up. These up-to-date data on HF in our region are in accordance with the international literature and could prove useful for Orthopaedic and Trauma surgeons for giving information to patients and their relatives.

Posterior Ankle and Hindfoot Arthroscopy

Introduction

Posterior ankle and hindfoot arthroscopy, performed with use of posteromedial and posterolateral portals with the patient in the prone position, has become an important diagnostic and therapeutic procedure for various intra-articular and extra-articular disorders.

Step 1 Position the Patient Prone

If you are planning to use fluoroscopy for surgery and wire distraction, position the patient prone, flex the contralateral knee, and wrap the contralateral leg to a padded holder.

Step 2 Apply Distraction If Necessary

Invasive distraction is used primarily to improve access to the ankle and subtalar joints.

Step 3 Place the Posterolateral and Posteromedial Portals Under Fluoroscopic Guidance

Using a mini-c-arm fluoroscopy unit to guide portal placement, place the posterolateral and posteromedial portals just lateral and medial to the Achilles tendon.

Step 4 Perform the Intra-Articular and/or Extra-Articular Procedure

Specific procedures include posterior arthroscopic arthrodesis of the subtalar joint, ankle arthrodesis, and excision of the os trigonum with tenolysis of the flexor hallucis longus tendon.

Step 5 Close the Arthroscopy Portals

Close the skin incision with nonabsorbable nylon sutures, and apply a sterile bulky dressing.

Step 6 Postoperative Care

Postoperatively, a plaster splint or walking boot with the foot in neutral is used for the first five to seven days.

Results

Posterior ankle and hindfoot arthroscopy was performed in 189 ankles (186 consecutive patients with a mean age of 37.1 years).

What to Watch For

IndicationsContraindicationsPitfalls & Challenges.

Tips and tricks for writing a scientific manuscript

An original scientific manuscript is the target for any researchers whose aim is to show the innovative results arising from the original intuitions that drove all their experiments. Time and patience are essential to decide how to present the data, how to conceive the tables and figures representing the main outcomes of the research, and how to read and mention the necessary references. Few basic rules may help in this difficult task. The first basic rule is: "do not follow the sequence of the paper". On the opposite, i) start writing the "Materials and Methods (or Patients and Methods when dealing with a clinical study)", ii) then write the "Results" section, iii) then, write the "Discussion" paragraph, in which the principal investigator explains the results and the innovations proposed, iv) then, write the "Introduction", which should be clear and concise. The last element to be written should be the "Abstract", which is the "interface" between the authors and the readers. The second basic rule is that any of the central chapters of the manuscript, i.e. "Materials and Methods" (MM), "Results" (R) and "Discussion" (D), should follow a methodical and sequential description of the topics in a "corresponding sequence of paragraphs". In other words, in the R and the D chapter sequence of the paragraphs should be linked to the sequence of the concepts described and discussed in the paragraphs of the MM chapter. Thus, a sequential description of concepts will be easily followed by the writers, facilitating both the authors in the organization of the data and the reader in finding a reasonable "answer" to all the aspects of the study mentioned in the MM chapter. In this article, these two rules are extensively described and several tips and tricks for each chapter are suggested to ease the composition of a scientific paper. Indeed, it may be possible to solve the complex problem of "writing a scientific paper" by means of separating it in main sections (chapters) and subsections (paragraphs) and dealing with them one by one. Naturally, this takes time and passion, but, as affirmed by Steve Jobs, "the only way to do great work is to love what you do".

Rehabilitation protocol after simultaneous anterior cruciate ligament reconstruction and high tibial osteotomy: introducing the concept of the individualized approach

Postoperative rehabilitation after simultaneous anterior cruciate ligament reconstruction and opening wedge high tibial osteotomy is a complex concept. Different osteotomy techniques, extremely selected patients, high expectations in returning to previous sport activities, and the different individual physical profile and performances make traditional chronological criteria impractical and unfeasible. This study presents a novel rehabilitation in which functional objective criteria are considered the key factors for standardizing a 4-step protocol. Each step is "individualized", based on the patient's response to the healing processes and to the different training phases, allowing for a safe return to sports competitions. This definitively implies a strict collaboration between patient, surgeon, physician and physiotherapists, as well as thorough and detailed patient education. Due to the high versatility of these new rehabilitation concepts, the application of the "individualized" steps described in this study may be broadened to include different sports medicine knee injuries that may benefit from a specific, detailed and carefully patient-centered rehabilitation project.

When math meets surgery: how to improve femoral interference screw alignment in ACL reconstruction. A cadaveric study

Transtibial femoral tunnel drilling is still an alternative technique in ACL reconstruction. Femoral interference screw divergence is a potential pitfall associated with transtibial tunnel technique, as angles greater than 15° jeopardize graft fixation. Our mathematical model theorizes the proper degrees of knee flexion during femoral screw insertion and the correct screwdriver position to obtain a minimal divergence of the screw in the femoral tunnel. The cadaveric study confirms our method. Mathematical model: using rototranslation matrices, a correlation is demonstrated between the ACLtibial- guide angle, the knee flexion, and the screwdriver position. A theoretical minimal divergence between femoral interference screw and the femoral tunnel is obtainable following these assumptions: 1) knee hyperflexion during femoral screw insertion is obtained adding a flexion corresponding to the ACL-tibial-guide angle to the flexion while drilling the femoral tunnel; 2) screwdriver position (through the AM portal) is kept parallel to tibial plateau at a rotation of 15° medial to tibial sagittal plane. Cadaveric study: 24 cadaver knees were used. The transtibial tunnel was drilled with an 8 mm drill bit with the help of an ACL tibial guide set at 55°. To simulate femoral tunnel direction, a 2.4 mm K. wire was drilled through the femur with a transtibial 7 mm offset femoral drill guide. To simulate the femoral screw direction, a second 2.4 mm K. wire was drilled from the femoral entry point of the first wire through the femur, with a cannulated screwdriver. Screwdriver direction and knee flexion during the simulation were obtained following two different methods: GROUP A (mathematical model group, 12 knees), screwdriver direction and knee flexion were calculated following the mathematical model; in GROUP B (control group, 12 knees), knee hyperflexion and screwdriver medialization were manually obtained by a senior surgeon. The divergence between the femoral interference screw and the femoral tunnel was identified as the angle formed by the two wires, measured on the plane formed by the direction of the wires. Mean divergence angles between the K. wires were significantly different (p< 0.05) between the groups: GROUP 1 (mathematical rule): 7.25° (SD 2.2); GROUP 2 (free-hand technique): 17.3° (SD 2.9). Our study shows that a minimal divergence between the femoral tunnel and the screwdriver can be achieved simply by following a mathematical rule for correct intraoperative knee flexion and screwdriver position without the need for any specialized instrumentation. Namely, during femoral interference screw insertion through the anteromedial portal: 1) the correct knee flexion is the sum between the knee flexion angle while drilling the transtibial femoral tunnel AND the ACL tibial guide angle used during tibial tunnel drilling; 2) Correct screwdriver position is parallel to the tibial plateau, engaging the femoral tunnel with a position of 15° medial to tibial sagittal plane. This simple concept has clinical relevance in helping the surgeons in obtaining an optimal alignment between the femoral tunnel and the femoral interference screw during transtibial ACL reconstruction. Furthermore, following the assumptions of this study, a starting knee flexion angle around 70° during femoral tunnel drilling seems preferable for ACL reconstruction when the transtibial tunnel technique is used. Indeed, because ACL-tibial-guide angles range commonly from 50° to 60° and in vivo, the maximal intraoperative knee flexion attainable is 130°, a starting knee flexion around 70° is optimal to allows for adding flexion angles up to 60° before reaching the physiological limit value of 130°.

Joint-line obliquity angle is significantly affected by hip abduction and adduction: A simulated analysis

PURPOSE

Different methods for quantifying joint-line obliquity (JLO) have been described, including joint-line obliquity angle (JLOA), Mikulicz joint-line angle (MJLA) and medial proximal tibial angle (MPTA). The goal of the present study was to quantify the variation of JLOA based on the position of the hip. The hypothesis of our study is that JLO is significantly influenced by the abduction/adduction of the limb, unlike MJLA.

METHODS

One hundred long-leg-weightbearing X-rays were used. At time 0 and after 30 days, two observers performed different measurements, including (1) distance between pubic symphysis and center of the femoral head, (2) distance between center of the femoral head and center of the ankle joint, (3) distance between center of the ankle and medial malleolus, (4) hip-knee-ankle angle, (5) MPTA, (6) lateral distal femoral angle, (7) joint-line congruency angle, (8) JLOA, (9) MJL and (10) angle between Mikulicz line and line perpendicular to the ground. The changes of the JLOA based on the position of the hip (abducted, neutral, bipedal stance adduction and monopodal stance adduction) were calculated with trigonometric formulas and with simulation on an orthopaedic planning digital software.

RESULTS

The JLOA change between adducted and abducted positions was on average 12.8° (SD 0.9 mm). The MJL did not vary significantly based on hip position.

CONCLUSIONS

The adduction/abduction of the lower limb has a considerable impact on JLOA. Methods like MJLA which are not affected by hip position should be preferred for JLO evaluation.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Hamstring grafts are tenogenic constructs for ACL reconstruction and Pulsed Electromagnetic Fields improve tendon specific markers expression. An in-vitro study

Hamstring tendons represent one of the commonest autologous graft used during ACL reconstruction. The harvest of the tendon and the time of tendon processing on the operating table, together with the pretensioning maneuvers and the permanence out of the joint during the time of surgery, might impair tendon derived cells (TCs) viability. The aim of the study was: i) to assess the effective viability of the TCs at the end of the surgical procedure; ii) to investigate if TCs viability and the expression of tendon specific markers may be improved through exposure to prolonged pulsed electromagnetic fields (PEMF) similar to that of clinical practice. Remnants of semitendinosus and gracilis tendons (discarded at the end of the ACL reconstruction) were collected from 13 healthy donors. To isolate TCs, the tendon tissue was minced and digested enzymatically with 0.3% type I collagenase in DMEM with continuous agitation for 15 h at 37°C. The isolated nucleated cells were then plated at 5x103 cells/cm2 in a complete medium composed of DMEM, 10% fetal bovine serum, 50 U/ml Penicillin, 50 mg/ml Streptomycin, 2 mM L-glutamine, and supplemented with 5 ng/ml basic fibroblast growth factor (b-FGF). They were maintained at 37 °C in a humidified atmosphere with 5% CO2, changing culture medium every 3 days. When they reached 80-90% of confluence, the cells were detached by incubation with trypsin/EDTA and then cultured at a density of 5x103 cells/cm2. TCs were cultured in complete medium for 7, 14, 21 days (in chamber slides, to optimize the final immunofluorescence analysis). The following cell cultures were set up: i) TCs cultured with differentiation medium + exposure to PEMF 8 h/day; ii) TCs cultured with differentiation medium without exposure to PEMF. The stimulation with PEMF was generated by a pair of electrical coils, connected with the generator of pulsed electromagnetic fields (PEMF generator system IGEA, Carpi, Italy, intensity of magnetic field = 1.5 mT, frequency = 75 Hz). At day 0, day 7, day 14 and day 21 immunofluorescence analysis was performed to evaluate the expression of tendon specific markers (collagen type I, collagen type VI, scleraxis) and proliferative markers (PCNA, beta-catenin). The TCs from the hamstring tendon fragments at the end of the ACL reconstruction were alive and they expressed markers of proliferation and tendon phenotype at the end of the culture period. The TCs in the presence of PEMF 8h/day showed a greater production of collagen type I, collagen type VI and scleraxis than TCs cultured without PEMF (p<0.05). The expression of these markers increased from 7 to 21 days of culture. The expression of proliferative markers in the presence of PEMF stimulus was significantly lower (p<0.05) than that of TCs cultured without PEMF. Hamstring tendons are not simple "tenoconductive" scaffolds but biologic alive tenogenic constructs rich in cells that can sustain tenogenic behavior and tendon matrix synthesis. Prolonged exposure to PEMF improves their phenotype. Thus, from a clinical perspective, the use of PEMF may represent a possible future strategy to positively influence the early phase of graft remodeling and, ultimately, improve the ligamentization process. Following these concepts, further studies might also exploit the anabolic role of PEMF as an adjunctive postoperative strategy in different tendon pathologies.

Tranexamic acid effects on cartilage and synovial tissue: an in vitro study for a possible safe intra-articular use

The possible toxic effects of intra-articular tranexamic acid (TA) are still debated. The aim of this study was to evaluate TA effects on human cartilage fragments and synovial biopsies. Explant culture of minced articular cartilage underwent prolonged TA exposure. Histological analysis, immunofluorescence and colorimetric assay for quantification of s-GAG and DNA were performed at the end term. Synoviocytes were cultured for 48h in presence of TA. Light microscopy and flow cytometry analysis were performed at the end of the exposure to TA and one week after the treatment. TA exposure did not influence i) the chondrocyte outgrowth and migration, ii) the expression of chondrogenic and proliferative markers and iii) the s-GAG/DNA ratio. TA treatment did not affect synoviocytes’ morphology and treated cells were phenotypically similar to control cells. This study demonstrated that TA does not negatively affect chondrocytes and synoviocytes cultured in vitro. Thus, our findings may be clinically relevant in order to validate the intra-articular TA administration during orthopedic procedures.

Treatment of medial and posteromedial knee instability: indications, techniques, and review of the results

Injuries of the posteromedial corner of the knee are relatively common. These can be isolated or combined with other ligament lesions. In some cases the treatment of postero-medial corner injuries is controversial. After a brief description of the anatomy and biomechanics of the medial side of the knee, this paper reviews the indications for isolated and multiligamentous medial/posteromedial corner injuries both in the acute and in the chronic setting. In addition, the most common surgical techniques for repair and reconstruction are described in addition to outcomes based upon a review of the literature.

One-step cartilage repair with minced chondral fragment on a composite scaffold: an in vitro human study at low oxygen tension

Minced cartilage fragments are a viable cell source for one stage cartilage repair. However, the joint surface is a low oxygen tension microenvironment and little evidence is present in literature regarding the behaviour of cartilage fragments in this peculiar condition. The aim of the study is i) to verify if low oxygen tension could negatively influence chondrocyte outgrowth from cartilage fragments into a Hyaluronic-Acid(HA)/fibrin scaffold and ii) to evaluate its effects on the behaviour of migrating chondrocyte, compared to normoxic condition. A slight decrease in chondrocyte migration and proliferation was observed in low oxygen tension cultures. Conversely, an increase in the expression of SOX9, β-catenin, HIFs, collagen-I and II (p<0.05) in migrating chondrocytes from low oxygen tension cultures was present. Thus, a long term- exposure at low oxygen tension seems to improve the chondrocytic phenotype expression of cell outgrowing from cartilage fragments onto a HA/fibrin scaffold.