Anatomic landmarks for a safe arthroscopic approach to the deep gluteal space: a cadaveric study / Hitos anatómicos para un abordaje artroscópico seguro del espacio glúteo profundo: un estudio cadavérico

SUMMARY: To determine the morphometric landmarks and anatomical variants relevant to the arthroscopic approach to the deep gluteal space. Twenty deep gluteal spaces from cadaveric specimens were dissected. The anatomical variants of the sciatic nerve (SN) were determined according to the Beaton and Anson classification. A morphometric study of the distances in the subgluteal space was carried out to define the anatomical references to achieve a safe arthroscopic approach for piriformis syndrome [GT-SN=Distance from greater trochanter (GT) to SN emergence; GT-IT=Distance from GT to ischial tuberosity (IT); GT-IGA=distance from GT to inferior gluteal artery (IGA) emergence; IT-SN=distance from IT to SN emergence; IT-IGA=distance from IT to IGA]. The SN showed the most frequent anatomical pattern with an undivided nerve coming out of the pelvis below the piriformis muscle (Beaton type A) in 16 specimens (80 %). The common peroneal nerve emergence in the subgluteal space through the piriformis muscle (PM) with the tibial nerve being located at the lower margin of the piriformis muscle (Beaton type B) was observed in 4 specimens (20 %). The morphometric measurements of the surgical area of study were: GT-SN=7.23 cm (±8.3); GT-IT=8.56 cm (±0.1); GT-IGA=8.46 cm (±0.97); IT-SN=5.28 cm (±0.73), IT- IGA=5.47 cm (±0.74). When planning surgery for the deep gluteal syndrome in adult patients, the fact that the emergence of the SN in the subgluteal space is approximately 7 cm from the greater trochanter and 5 cm from the ischial tuberosity must be considered.

RESUMEN: El objetivo del estudio fue determinar referentes morfométricos y variantes anatómicas relevantes en el abordaje artroscópico del espació subglúteo. Se disecaron veinte regiones glúteas procedentes de cadáver. Las variaciones anatómicas del nervio ciático (SN) se determinaron de acuerdo con la clasificación de Beaton y Anson. Se llevó a cabo un estudio morfométrico de distancias en el espacio subglúteo, con objeto de determinar referencias que permitan un abordaje artroscópico seguro del sindrome piriforme [GT-SN= distancia trocánter mayor (GT) a la emergencia del nervio ciático (SN); GT-IT= distancia GT a la tuberosidad isquiática (IT); GT-IGA= distancia GT a la emergen- cia de la arteria glútea inferior (IGA); IT-SN= distancia IT a la emergencia del SN; IT-IGA= distancia IT a la IGA]. El patrón más frecuente del SN fue su emergencia no dividida por el margen inferior del músculo piriforme (tipo A Beaton) en 16 especímenes (80 %). La salida del nervio fibular común a través del músculo piriforme (PM) con el nervio tibial localizado en el margen inferior del PM (tipo B Beaton) se observó en 4 especímenes (20 %). Las medidas en el área quirúrgica de estudio fueron: GT-SN= 7,23 cm ± 8,3; GT-IT= 8,56 cm ± 0,1; GT-IGA= 8,46 cm ± 0,97; IT-SN= 5,28 cm ± 0,73 IT-IGA= 5,47 cm ± 0,74. En la cirugía del síndrome glúteo profundo en adultos, debe considerarse que la sa- lida del SN hacia el espacio subglúteo tiene lugar aproximadamente a 7 cm del GT y a 5 cm de la IT.

Promising radiological outcome after repair of acetabular chondral defects by microfracture augmented with chitosan-based scaffold: mid-term T2 mapping evaluation.

PURPOSE: Radiological evaluation of the repair tissue produced after arthroscopic treatment of acetabular chondral lesions associated with femoroacetabular impingement (FAI) by the chitosan-based scaffold. METHODS: Patients of age 18-55 years with clinical and radiological features of FAI and non-arthritic non-dysplastic hips were selected for arthroscopic treatment. Full-thickness acetabular chondral defects were filled with chitosan-based scaffold material after microfracture. T2 mapping was carried out for all patients after 24 months using a 1.5-T machine. Nine regions of interest (ROIs) were localized from three consecutive sagittal slices including the area of repair. T2 relaxation times of ROIs in the repair area were compared with the corresponding posterior cartilage. RESULTS: Twenty-one patients, 17 men and 4 women, underwent arthroscopic treatment of full-thickness acetabular chondral defects with mean size of 3.6 ± 1 cm2 (range 2-6 cm2). Zone 2 was affected in all cases while zone 3 was involved in 13 cases. T2 relaxation values were collected from 189 ROIs for quantitative analysis. Within the peripheral repair area, the mean T2 value was 49.1 ± 7.2 ms (ms), while ROIs of the central repair area had mean T2 values of 50.2 ± 7.1 ms. Posterior cartilage showed mean T2 value of 46.2 ± 7.6 ms CONCLUSION: Arthroscopic microfracture of large full-thickness acetabular chondral defects with chitosan-based scaffold produced a homogenous repair tissue similar to the corresponding native cartilage of the same joint on quantitative T2 mapping at mid-term follow-up. CLINICAL RELEVANCE: augmentation of the microfracture by chitosan-based scaffold is a promising modality for treatment of large full-thickness acetabular defects. LEVEL OF EVIDENCE: IV.

Rehabilitation protocols in unstable trochanteric fractures treated with cephalomedullary nails in elderly: current practices and outcome.

BACKGROUND: Optimal rehabilitation treatment after surgery for fixation of unstable trochanteric fractures is challenging in elderly patients. PURPOSE: The objective of this study is to analyse the existing literature on available rehabilitation protocols with regards to permitting or restricting early weight bearing following fixation of unstable trochanteric fractures treated by the use of cephalomedullary nails in patients at least 65 years of age. METHODS: A systematic review was performed based on the checklist of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Studies published between 1948 and 2018 on elderly patients with unstable trochanteric fractures treated with cephalomedullary nails that offered information on the postoperative rehabilitation protocol have been selected. Subsequently, the results and complications have been analysed according to the protocols. RESULTS: Fifteen of the 7056 initial articles have been selected for analysis. Authors who did not restrict weight bearing to their patients reported a shorter hospitalization time and a lower orthopaedic complication rate but a greater systemic complication rate, worse functional scores, and a higher reoperation and mortality rates. Those results should be taken with caution because of the heterogeneity of provided clinical information and the fact that none of the included studies considered the different rehabilitation protocols as study variables to analyse its influence on the results. CONCLUSION: With evidence available to date, there is no clear agreement on the postoperative rehabilitation protocol following fixation of an unstable trochanteric fracture by cephalomedullary nail in the elderly.

Femoroacetabular Impingement: What the Surgeon Wants to Know.

Femoroacetabular impingement (FAI) is increasingly recognized as a risk factor for early hip degeneration in young active patients. The diagnosis depends on clinical examination and proper imaging that should be able to identify abnormal and sometimes subtle morphological changes. Labral tears and cartilage lesions rarely occur without underlying bone abnormalities. Surgical approaches to treat FAI are increasing significantly worldwide, even without a clearly defined consensus of what should be accepted as the standard imaging diagnosis for FAI morphology.Hip abnormalities encompass many variations related to the shape, size, and spatial orientation of both sides of the joint and can be difficult to characterize if adequate imaging is not available.This article presents a comprehensive review about the information orthopaedic surgeons need to know from radiologists to plan the most rational approach to a painful hip resulting from a mechanical abnormality.

Arthroscopic Repair of Acetabular Cartilage Lesions by Chitosan-Based Scaffold: Clinical Evaluation at Minimum 2 Years Follow-up.

PURPOSE: To evaluate the functional outcome of using chitosan-based material in our patients after 2 years of follow-up. METHODS: Nonarthritic nondysplastic femoroacetabular impingement patients with an acetabular chondral lesion, 18 to 55 years of age, were included for arthroscopic repair between May 2013 and July 2015. Full-thickness chondral defects ≥2 cm2 were filled with chitosan-based implant after microfractures. Follow-up consisted of alpha angle assessment and clinical outcome in the form of the Non Arthritic Hip Score (NAHS), International Hip Outcome Tool 33 (iHOT33), Hip Outcome Score of Activities of Daily Living (HOS-ADL), and Hip Outcome Score of Sports Specific Scale (HOS-SSS). RESULTS: Twenty-three patients were included. The mean follow-up was 38.4 ± 7.0 months (range, 24-50 months). The mean defect size was 3.5 ± 1.0 cm2, principally involving zone 2 and to a lesser extent in zones 1 and 3. Using femoroplasty, the alpha angle was corrected from a mean 70.5 ± 6.3° to 44.3 ± 4.9° (P = .00001). Significant improvement occurred comparing the preoperative to the first-year postoperative patient-reported outcomes: P = .00001 for the NAHS, P = .00004 for the iHOT33, P = .00005 for the HOS-ADL, and P = .0002 for the HOS-SSS. No statistically significant change has been observed in the patient-reported outcomes obtained at the endpoint when compared with the first-year values (P = .13 for the NAHS, P = .21 for the HOS-ADL, and P = .29 for the HOS-SSS), except for the iHOT33, which showed further significant improvement (P = .02). Up to 91% of the patients met or exceeded the minimal clinically important difference. One patient needed total hip arthroplasty. Perineal hypoesthesia occurred in 3 patients, who recovered within 2 to 6 weeks, and 1 patient needed a prolonged physiotherapy program for postoperative muscular stiffness. CONCLUSIONS: The arthroscopic combined treatment of microfractures and chitosan-based scaffold has maintained satisfactory clinical outcomes in 91% of the patients with s large (≥2 cm2) full-thickness acetabular chondral defect associated with femoroacetabular impingement at a mean follow-up of 38.4 months. The study could not definitely draw any conclusion regarding the safety of chitosan-based material for use in the hip joint. LEVEL OF EVIDENCE: Level IV, case series.

Cam Femoroacetabular Impingement as a Possible Explanation of Recalcitrant Anterior Knee Pain.

We present a case of a patient with chronic anterior knee pain (AKP) recalcitrant to conservative treatment who returned to our office for severe hip pain secondary to Cam femoroacetabular impingement (Cam FAI) at 10 months after the onset of knee pain. This case highlights the fact that the main problem is not in the patella but in the hip in some patients with AKP. We hypothesize that there is an external femoral rotation in order to avoid the impingement and therefore the hip pain in patients with Cam FAI. This functional femoral rotation could provoke a patellofemoral imbalance that may be, in theory, responsible for patellofemoral pain in this particular patient. In our case, Cam FAI resolution was related to the resolution of AKP.

Reliability of Tönnis classification in early hip arthritis: a useless reference for hip-preserving surgery.

INTRODUCTION: The Tönnis classification is widely accepted for grading hip arthritis, but its usefulness as a reference in hip-preserving surgery is yet to be demonstrated. We aimed to evaluate reproducibility of the Tönnis classification in early stages of hip osteoarthritis, and thus determine whether it is a reliable reference for hip-preserving surgery. MATERIALS AND METHODS: Three orthopaedic surgeons with different levels of experience examined 117 hip X-rays that were randomly mixed of two groups: a group of 31 candidates for hip-preserving surgery and a control group of 30 patients that were asymptomatic with respect to the hip joint. The surgeons were asked to rate an eventual osteoarthritis according to the Tönnis classification. After 2 months, the surgeons were asked to re-evaluate the X-rays in a random order. Intra- and interobserver reliabilities were calculated by comparing the observers' two estimations using Kappa statistics. RESULTS: Kappa values for interobserver reliability were slight or fair (range 0.173-0.397). Kappa values for intraobserver reproducibility were fair (range 0.364-0.397). Variance in grading no and slight osteoarthritis was the most frequent cause for intra- and interobserver disagreements (76.3 and 73.01% of the non-concordant observations, respectively). The confidence interval analysis showed that the observers' experience did not affect reproducibility. CONCLUSIONS: The Tönnis classification is a poor method to assess early stages of hip osteoarthritis. These findings suggest that its routine use in therapeutic decision-making for conservative hip surgery should be reconsidered.

A Novel Association between Femoroacetabular Impingement and Anterior Knee Pain.

Background. For a long time it has been accepted that the main problem in the anterior knee pain (AKP) patient is in the patella. Currently, literature supports the link between abnormal hip function and AKP. Objective. Our objective is to investigate if Cam femoroacetabular impingement (FAI) resolution is related to the outcome in pain and disability in patients with chronic AKP recalcitrant to conservative treatment associated with Cam FAI. Material and Methods. A retrospective study on 7 patients with chronic AKP associated with FAI type Cam was performed. Knee and hip pain were measured with the visual analogue scale (VAS), knee disability with the Kujala scale, and hip disability with the Nonarthritic Hip Score (NAHS). Results. The VAS knee pain score and VAS hip pain score had a significant improvement postoperatively. At final follow-up, there was significant improvement in all functional scores (Kujala score and NAHS). Conclusion. Our finding supports the link between Cam FAI and AKP in some young patients. Assessment of Cam FAI should be considered as a part of the physical examination of patients with AKP, mainly in cases with pain recalcitrant to conservative treatment.

Arthroscopic Treatment of Hip Chondral Defects With Bone Marrow Stimulation and BST-CarGel.

Microfracture, the current standard of care for the treatment of non-degenerative chondral lesions in the hip joint, is limited by the poor quality of the filling fibrocartilaginous tissue. BST-CarGel (Piramal Life Sciences, Laval, Quebec, Canada) is a chitosan-based biopolymer that, when mixed with fresh, autologous whole blood and placed over the previously microfractured area, stabilizes the blood clot and enhances marrow-triggered wound-healing repair processes. BST-CarGel has been previously applied in the knee, with statistically significant greater lesion filling and superior repair tissue quality compared with microfracture treatment alone. In this report we describe the application of BST-CarGel for the arthroscopic treatment of hip chondral lesions. Our preliminary data suggest that our BST-CarGel procedure provides high-quality repair tissue and therefore may be considered a safe, cost-efficient therapeutic choice for the treatment of hip chondral defects.

Promising short-term results following selective bundle reconstruction in partial anterior cruciate ligament tears.

BACKGROUND: The different functions of the two anterior cruciate ligament (ACL) bundles have increased interest in tears of only one of these two bundles. The purpose of this study was to assess the outcome of selective reconstruction of an injured bundle of isolated anteromedial bundle (AMB) or posterolateral bundle (PLB) tears. METHODS: Consecutive series of 147 ACL reconstructions was prospectively analyzed. Patients with partial ACL tears who underwent selective bundle reconstructions were studied. Stability was assessed with the Lachman, anterior-drawer and pivot-shift tests and KT-1000. Functional assessment was performed with Lysholm and Tegner questionnaires. The preoperative MRI was analyzed to detect differences from arthroscopic findings. RESULTS: Twenty-eight patients (19%) were included. The minimum follow-up period was 30months. Eighteen had AMB and 10 PLB tears. Only 19% of their MRI's were categorized as partial ACL tears. The Lysholm score improved from 66.1/65.5 to 96.6/95.2 in the AMB/PLB groups, respectively (p<0.001). The same or no more than one level lower Tegner score was restored. The pivot-shift, Lachman and anterior-drawer tests were negative in all cases (p<0.001). Two reconstructed AMBs developed extension loss due to Cyclops lesions and were resolved surgically. CONCLUSIONS: The technique provided excellent functional scores with normalized stability and a return to previous level of activity with a low rate of minor complications at a minimum 2.5years' follow-up. Arthroscopic examination was the most reliable tool for properly diagnosing and treating a condition observed in almost one out of every five ACL reconstructed knee in this series. LEVEL OF EVIDENCE: Therapeutic case series; level 4.

Myxoid tumor associated to migration of a suspensory fixation device of a reconstructed anterior cruciate ligament: a case report.

A 16-year-old male who had undergone 6 months before an anterior cruciate ligament (ACL) reconstruction with an autologous hamstring graft fixed with a suspensory fixation device (XoButton device; ConMed Linvatec, Largo, FL), complained of a slightly painful mass in the distal posterolateral aspect of the thigh. The knee was otherwise stable. A 79 × 60 × 17 mm multilobulated tumor surrounding the implant device was observed in magnetic resonance images. The revision arthroscopy showed an intact ACL graft. The tumor was excised through a longitudinal posterolateral approach. It had a myxoid appearance. The undamaged implant was also removed. Two months after surgery, the patient was already asymptomatic. Although most fixation device problems occur in the perioperative period due to an inadequate technique which may lead to graft instability, this case reminds clinicians of the possibility of later developing clinically relevant complications with suspensory fixation devices.

Prospective comparative study between two different fixation techniques in meniscal allograft transplantation.

PURPOSE: To compare the functional and radiographic results between two different horn fixation techniques for meniscal allograft transplant. METHODS: This is a prospective study of 88 meniscal allograft transplants with a mean 5-year follow-up. Forty transplants were performed on the medial compartment and 48 on the lateral compartment. The same surgeon performed all surgeries. Thirty-three grafts were fixed only with sutures (Group A) and 55 only with bony fixation (Group B). Both groups were comparable in terms of age, laterality, time since meniscectomy and preoperative functional and radiographic status. Functional assessment was done with Lysholm and Tegner scores and the Visual Analogical Scale for pain. Joint space narrowing was evaluated in the Rosenberg view. RESULTS: There was a significant improvement in Lysholm, Tegner and VAS scores without differences between Group A and Group B (n.s.). Radiographic evaluation did not show any joint space narrowing (n.s.). No differences in the comparison of all the variables of the two compartments were found. There were complications in 33.3 % of patients in Group A that including 7 graft tears (21.4 %) and in which there was an allograft failure rate of 9 %. Group B showed complications in 16.4 % of the patients and included 4 graft tears (7.3 %, n.s.) with an allograft failure rate of 3.6 %. CONCLUSIONS: Meniscal allograft transplantation with either technique provided good functional and radiographic results at mid-term follow-up. Both graft fixation methods showed no differences relative to functional and radiographic results. There was a considerably higher rate of complications in transplantations performed with the only-suture technique than those with bony fixation, although the difference was not statistically significant with the numbers available. The results suggest that similar functional results should be expected whether the meniscal graft includes bone plugs or not. However, graft tears seem to happen more frequently if the MAT is performed without bony fixation. LEVEL OF EVIDENCE: Prospective comparative study, Level II.

Hip labral cyst caused by psoas impingement.

Hip labral impingement can cause labral tears and secondary paralabral cyst formation. Femoroacetabular impingement is the main cause of labral impingement, but other conditions such as iliopsoas tendon impingement are described. There is no description of labral cyst resulting from psoas impingement treated arthroscopically in the literature. We present the case of a young sportsman with groin pain caused by psoas impingement with a labral tear and secondary paralabral cyst who was treated arthroscopically by cyst debridement, psoas tenotomy, and labral repair.

There is no relation between mild malalignment and meniscal extrusion in trauma emergency patients.

OBJECTIVE: To evaluate whether an alteration of the lower limb axis is associated with meniscal extrusion. MATERIALS AND METHODS: Ninety-four patients who had complained of knee pain with good knee function and had a knee magnetic resonance image (MRI) and a full-length X-ray taken of the lower limb were included in the study. Meniscal extrusion was measured in the coronal MRI. Subluxation of the meniscus was considered minor or physiological if ≤ 3 mm, and major if >3 mm. The extrusion as a percentage of meniscus size was also calculated. Knee alignment (varus, negative value; valgus, positive value) was correlated with the presence of minor and major extrusion. RESULTS: There were varus knees in 61 cases (58.7%), with a mean measured deviation of -2.63°. Valgus knees were observed in 27 knees (26%) and had a mean deviation of 2.22°. The medial meniscus showed major extrusion in 18 cases (17.3%). It corresponded to 44.7% of the meniscus size. The lateral menisci showed no subluxation in most cases. There was no correlation between alignment and meniscal extrusion in this series, either for the medial meniscus (p = 0.760) or for the lateral meniscus (p = 0.381). CONCLUSIONS: In patients complaining of knee pain with good knee function, there is no relationship between mild malalignment and the degree of meniscus extrusion.

Outcome after partial medial meniscus substitution with the collagen meniscal implant at a minimum of 10 years' follow-up.

PURPOSE: The aim of the study was to evaluate the clinical outcome of a collagen meniscus graft implanted in an injured medial meniscus after a minimum of 10 years' follow-up. METHODS: Twenty-five patients underwent arthroscopic implantation of the collagen meniscus device. They had either persistent compartmental joint line pain due to a previous medial meniscus resection (5 cases) or a large irreparable meniscus tear at arthroscopy (20 cases). Implant failure was defined as infection due to the implant or mechanical failure of the device. Twenty-two patients returned for clinical, functional, and radiographic evaluation. Magnetic resonance imaging was also performed and was analyzed with the criteria of Genovese et al. (where type 3 indicates normal and type 1 indicates completely abnormal). All the aforementioned evaluations were carried out at a minimum of 10 years (range, 10.1 to 12.5 years) after the procedure. RESULTS: The mean Lysholm score improved from 59.9 preoperatively to 89.6 at 1 year (P < .001), and it was 87.5 at final follow-up (P < .001). The results were good or excellent in 83% of the population. No differences were observed when we compared the Lysholm score at 1 year of follow-up with the score at final follow-up (P > .05). The mean pain score on a visual analog scale improved by 3.5 points at final follow-up. Patient satisfaction with the procedure was 3.4 of 4 points. Radiographic evaluation showed either minimal or no narrowing of the joint line. Magnetic resonance imaging showed type 2 in 64% of cases and type 3 in 21%. All cases showed less volume than expected (size type 2 in 89%). The failure rate in the patient population was 8% (2 of 25). There were no complications related to the device. CONCLUSIONS: Although there were several different types of patients and acute and chronic tears were treated in a limited number of patients, meniscal substitution with the collagen meniscal implant provides significant pain relief and functional improvement after a minimum of 10 years' follow-up. The implant generally diminished in size, but the procedure proved to be safe and had a low rate of implant failure on a long-term basis. No development or progression of degenerative knee joint disease was observed in most cases. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Allogenic labral transplantation in hip instability following arthroscopic labrectomy.

The acetabular labrum augments femoral head coverage within the acetabulum and contributes to hip joint stability. This has led to an increasing interest in procedures dedicated to preservation of the labrum. An allogenic labral transplantation performed in a patient who had previously undergone a partial labral resection is presented.

[Learning curve of arthroscopic hip surgery]. / Curva de aprendizaje en la cirugía artroscópica de cadera.

BACKGROUND: Hip arthroscopy has become an increasingly used technique in orthopedic surgery; the learning curve of this procedure has been discussed recently. The purpose of this study is to assess the learning curve of arthroscopic hip surgery using the complications occurred during the surgery as an objective parameter to measure the outcomes. METHODS: Hip arthroscopic surgeries were performed. Patients were divided into two groups, group A corresponded to the learning curve of the first surgeon and group B includes the remaining surgeries. The demographic, surgical, functional and complications data for both groups were collected. RESULTS: Group A: 30 patients were included, the traction time during surgery was a mean of 75 minutes (range: 45-120). Five complications occurred (16.6%), all of them related to transient neuropraxia of the pudendal nerve. Group B: 67 patients were included, traction time during surgery was a mean of 63 minutes (range: 35-90), 2 complications (2.9%) occurred. CONCLUSIONS: Before performing hip arthroscopy it is necessary to have knowledge of arthroscopic surgery and the regional anatomy, and to have received specific training, given that this technique involves a long learning curve.

Meniscal allograft transplantation without bone blocks: a 5- to 8-year follow-up of 33 patients.

PURPOSE: The purpose of this study was to evaluate the functional and radiographic results on a midterm basis, as well as complications, in an initial series of meniscal allograft transplantations performed with suture fixation without any bone block. METHODS: A series of 33 meniscal allograft transplantations were performed at our institution from January 2001 to October 2003. Inclusion criteria were patients with compartmental joint line pain due to a previous meniscectomy. There were 24 men and 9 women with a mean age of 38.8 years (range, 21 to 54 years). The functional outcomes were evaluated by use of Lysholm and Tegner scores at a mean and minimum follow-up of 6.5 years and 5 years, respectively. A visual analog scale for pain was also used. Radiographic assessment included joint space narrowing on the Rosenberg view and magnetic resonance imaging evaluation. RESULTS: The Lysholm and Tegner scores significantly improved from 65.4 to 88.6 (P < .001) and from 3.1 to 5.5 (P < .001), respectively, after surgery. The visual analog scale score significantly dropped from 6.4 to 1.5 (P < .001). The radiographic evaluation did not show any joint space narrowing (P = .38). Meniscal extrusion was a constant finding, averaging 36.3% of total meniscal size. According to the Van Arkel criteria, the survival rate was 87.8% at 6.5 years. The rate of complications was 33%. CONCLUSIONS: This study suggests that this procedure provides significant pain relief and functional improvement in selected symptomatic individuals on a midterm basis. However, there was a high rate of complications (33%) and revision surgery. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Anatomic single-bundle anterior cruciate ligament reconstruction from the anteromedial portal: evaluation of transverse femoral fixation in a cadaveric model.

PURPOSE: The purpose of this study was to assess the risk of injury to the posterolateral structures of the knee when performing anterior cruciate ligament reconstruction from the anteromedial portal while fixing the graft with a femoral cross-pin system. METHODS: The anterior cruciate ligament was reconstructed arthroscopically with hamstring graft in 10 fresh cadaveric knees. Femoral fixation was performed with a cross-pin system. This was originally developed for a transtibial drilling technique. A femoral tunnel measuring 30 mm in length was drilled through the anteromedial portal in each knee. The knee flexion angle was set at 110 degrees . Lateral dissection was then performed to measure the distances from the cross-pin system to the lateral collateral ligament, the popliteus tendon, the lateral gastrocnemius tendon, and the peroneal nerve. RESULTS: The lateral collateral ligament was partially torn by the pin in 1 case. In 8 cases the distance to the lateral collateral ligament was shorter than 3 mm (range, 0 to 2.43 mm). In 7 specimens, the cross-pin system was within 4.5 mm of the popliteus tendon. The lateral gastrocnemius tendon was pierced by the cross-pin device in 2 cases. The minimal distance to the peroneal nerve was 23.89 mm. CONCLUSIONS: Fixation of a hamstring graft with a cross-pin system initially developed for an upper femoral tunnel, following the aforementioned technique, presents the possibility of a high risk of injury to the lateral collateral ligament. The popliteus tendon and the lateral gastrocnemius tendon may also be injured. CLINICAL RELEVANCE: The risk of injury to the lateral stabilizers of the knee suggests discarding the technique used in this study.