Substantial influence of psychological factors on return to sports after anterior shoulder instability surgery: a systematic review and meta-analysis.

PURPOSE: This systematic review and meta-analysis aimed to (1) determine the proportion of patients who underwent anterior shoulder instability surgery and did not return to sports for psychological reasons and (2) estimate differences in psychological readiness scores between patients who did and did not return to sports. METHODS: The EBSCOhost/SPORTDiscus, PubMed/Medline, Scopus, EMBASE and Cochrane Library databases were searched for relevant studies. The data synthesis included the proportion of patients who did not return to sports for psychological reasons and the mean differences in the psychological readiness of athletes who returned and those who did not return to sports. Non-binomial data were analysed using the inverse-variance approach and expressed as the mean difference with 95% confidence intervals. RESULTS: The search yielded 700 records, of which 13 (1093 patients) were included. Fourteen psychological factors were identified as potential causes for not returning to sports. The rates of return to sports at any level or to the preinjury level were 79.3% and 61.9%, respectively. A total of 55.9% of the patients cited psychological factors as the primary reason for not returning to sports. The pooled estimate showed that patients who returned to sports had a significantly higher Shoulder Instability-Return to Sport After Injury score (P < 0.00001) than those who did not, with a mean difference of 30.24 (95% CI 24.95-35.53; I2 = 0%; n.s.). CONCLUSIONS: Psychological factors have a substantial impact on the rate of return to sports after anterior shoulder instability surgery. Patients who returned to sports had significantly higher psychological readiness than those who did not return to sports. Based on these results, healthcare professionals should include psychological and functional measurements when assessing athletes' readiness to return to sports. LEVEL OF EVIDENCE: Level IV.

The Reliability of Acromioclavicular Joint Dislocation Classification Systems: A Comparison Between the Rockwood and Kraus Classifications.

Background: The Rockwood system for the classification of acute acromioclavicular (AC) joint dislocations has been associated with a lack of reliability. A novel system has been proposed (Kraus classification) that is based on dynamic posterior translation of these injuries. Purpose: To assess the interobserver and intraobserver reliability of the Rockwood and Kraus classification systems and also to examine the impact of surgeon experience on the assessments. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Included were 45 patients with acute AC joint injuries who underwent a radiographic examination using standard bilateral AP and modified Alexander views. For interobserver reliability, 6 shoulder surgeons (expert group) and 6 orthopaedic residents (novice group) reviewed the radiographs to classify injuries according to the Rockwood and Kraus classifications; for each categorization, the participants chose between nonoperative management and surgical treatment. The evaluation was repeated 6 weeks later to determine intraobserver reliability. Kappa (κ) coefficients and their 95% CIs were used to compare interobserver and intraobserver reliability for each classification system according to assessor experience. Statistical differences were considered significant when the upper and lower boundaries of the 95% CI did not overlap. Results: The overall interobserver agreement for diagnosis (both novice and expert groups) was moderate (κ = 0.52 [95% CI, 0.51-0.54]) for the Rockwood classification and substantial (κ = 0.62 [95% CI, 0.53-0.65]) for the Kraus classification; however, no significant differences were observed between the κ values. The overall interobserver agreement for treatment selection was substantial when using both the Rockwood (κ = 0.78 [95% CI, 0.72-0.81]) and Kraus (κ = 0.77 [95% CI, 0.66-0.87]) classifications. The overall intraobserver agreement for diagnosis was substantial using both the Rockwood (κ = 0.65 [95% CI, 0.61-0.67]) and Kraus (κ = 0.73 [95% CI, 0.69-0.75]) classifications. There were no significant differences between the novice and expert groups on any of the evaluations. Conclusion: The Kraus system was slightly more reliable than the Rockwood system for classifying AC joint injuries both between assessor groups and overall. The level of surgeon experience had no impact on the evaluations.

New precontoured long locking plate for proximal metadiaphyseal fractures of the humerus: a cadaveric study for its use with the minimally invasive technique.

BACKGROUND: The purpose of this study was to identify nerves at risk when using a minimally invasive plate osteosynthesis precontoured long proximal humerus locking plate and to evaluate the risk of injury to deltoid insertion and brachialis muscle. METHODS: Ten cadaveric upper limb specimens were used. A transdeltoid anterolateral approach was performed proximally and a second anterior approach was performed distally. A 14-hole "low" long precountored ALPS locking plate (Biomet Trauma; Zimmer Biomet, Warsaw, IN, USA) was used. Subsequently, anatomic dissection to measure the anatomic relationship of the plate with the deltoid insertion, with the brachialis muscle, and with the axillary, radial, and musculocutaneous nerves was performed. RESULTS: The mean humeral length was 302 mm (standard deviation 52.3, 99% confidence interval: 259.3-344.6). In 6 specimens, the axillary nerve was located at the level of the third row of holes of the plate; in 3 specimens, at the level of the fourth row; and in one specimen, at the level of the second row. The distance between the plate and the musculocutaneous nerve was on average 10.2 mm (standard deviation 4, 99% confidence interval: 6.9-13.5) and between the plate and the radial nerve was on average 7.9 mm (standard deviation 4.7, 99% confidence interval: 4-11.8). The plate pierced the anterior distal fibers of the deltoid in all specimens. In 8 specimens, no brachialis muscle fibers were located under the plate. CONCLUSIONS: The use of the long precontoured 14-hole ALPS locking plate with the minimally invasive plate osteosynthesis technique, previously identifying the axillary and musculocutaneous nerves, is feasible; however, the distances between the plate and the nerves remain low, so caution should be maintained. Despite the curved design of the plate, the deltoid insertion is partially compromised in all cases.

Suprapectoral biceps tenodesis with bicortical drilling procedures: anatomic analysis of chondral and axillary nerve risk with transhumeral pin guide.

BACKGROUND: Many biceps tenodesis (BT) procedures are described for treating proximal biceps pathology. Axillary nerve injury has been reported during BT using bicortical drilling techniques with variable results depending on the location. In addition, there is a risk of potential articular damage during suprapectoral BT. We sought to determine the distance between the axillary nerve and the posterior passage of a bicortical pin, as well as the risk of articular damage, and to analyze whether a lateral inclination of the pin could avoid the chondral risk during suprapectoral BT with bicortical drilling. METHODS: Ten cadaveric shoulders were divided into 2 groups. In the first group, we determined the axillary nerve distance from the posterior exit point of 3 pins in a suprapectoral position 15 mm distal to the humeral cartilage: perpendicular, 10° caudal, and 20° caudal inclination. We measured 2 distances from the pin: to the axillary nerve and to the cartilage border. In the second group, we set one pin at the same perpendicular position and set the second pin 15° laterally tilted to determine its extra-articular passage. RESULTS: No pin injured the nerve, whereas all pins showed a transchondral direction. The 20° caudal inclination was the nearest to the nerve (18.8 mm [95% confidence interval, 5.5-32 mm]), but the perpendicular position was the safer position (38.8 mm [95% confidence interval, 28-49.6 mm]). Tilting the pin direction 15° laterally prevented cartilage damage (P = .008). CONCLUSIONS: Suprapectoral BT with bicortical drilling performed 15 mm distal to the humeral cartilage is a safe procedure regarding the axillary nerve. A potential humeral chondral injury could be prevented with 15° of lateral inclination of the pin guide.

Knee Examination under Anesthesia: Development of a Predictive Score for Partial Anterior Cruciate Ligament Tears.

PURPOSE: To determine the accuracy of knee examination under anesthesia (EUA) and develop a prognostic score for partial anterior cruciate ligament (ACL) tears. MATERIALS AND METHODS: A total of 229 patients with an ACL injury were included. Knee EUA was performed using the Lachman test, pivot shift test and arthrometric maximum manual side-to-side difference (AMMD) test. The arthroscopic examination is the gold standard for the diagnosis of partial and complete ACL tears, which was compared with EUA findings. Multivariate logistic regression was estimated, and the significant variables were used to develop a predictive score. RESULTS: The relative risk for a complete tear with Lachman 2+ was 8.55 (range, 3.5 to 20.7) and 53.04 (range, 6.7 to 417) with Lachman 3+, compared to Lachman 1+. Negative pivot shift was reported in 23 cases in the partial tear group (76.7%) and in 22 in the complete tear group (11.1%). The AMMD was 3.5 mm in the partial tear group and 5.4 mm in the complete tear group (p＜0.05). A prognostic score of less than five suggested the presence of a partial ACL tear. The score showed 81.1% sensitivity and 68.7% specificity. CONCLUSIONS: Partial ACL tears can be differentiated from complete tears with Lachman test, pivot shift test, and AMMD test.

The effect of tunnel placement on bone-tendon healing in anterior cruciate ligament reconstruction in a goat model.

BACKGROUND: Misplacement of the bone tunnels is one of the main causes of graft failure of anterior cruciate ligament surgery. HYPOTHESIS: Anatomic tunnel placement in anterior cruciate ligament surgery reconstruction will lead to improved outcomes, including biological ingrowth and biomechanical properties, when compared with nonanatomic tunnel placement. STUDY DESIGN: Controlled laboratory study. METHODS: Anterior cruciate ligament surgery reconstructions were performed on 3 different groups of goats (1 anatomic tunnel placement group and 2 different nonanatomic tunnel placement groups, with 10 goats in each group). For each group of 10 knees, 3 knees were used for histologic evaluation (bone tunnel enlargement, number of osteoclasts at the bone tendon interface, and revascularization of the graft) and 7 knees were used for biomechanical testing (anterior tibial translation, in situ force, cross-sectional area, and ultimate failure load). Animals were sacrificed at 12 weeks after surgery. RESULTS: The anatomic tunnel placement group showed less tunnel enlargement on the tibial side, fewer osteoclasts on both the tibial and femoral sides, and more vascularity in the femoral side when compared with the 2 nonanatomic reconstruction groups. Biomechanically, the anatomic tunnel placement group demonstrated less anterior tibial translation and greater in situ force than both nonanatomic tunnel placement groups. CONCLUSION: Anatomic tunnel placement leads to superior biological healing and biomechanical properties compared with nonanatomic placement at 12 weeks after anterior cruciate ligament surgery reconstruction in a goat model. CLINICAL RELEVANCE: The findings of this study demonstrate the importance of anatomic tunnel placement in anterior cruciate ligament surgery reconstruction.

Tibiofemoral joint contact area and pressure after single- and double-bundle anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study was to compare the tibiofemoral contact area and pressure after single-bundle (SB) and double-bundle (DB) anterior cruciate ligament (ACL) reconstruction by use of 2 femoral and 2 tibial tunnels in intact cadaveric knees. METHODS: Tibiofemoral contact area and mean and maximum pressures were measured by pressure-sensitive film (Fujifilm, Valhalla, NY) inserted between the tibia and femur. The knee was subjected to a 1,000-N axial load by use of a uniaxial testing machine at 0 degrees , 15 degrees , 30 degrees , and 45 degrees of flexion. Three conditions were evaluated: (1) intact ACL, (2) SB ACL reconstruction (n = 10 knees), and (3) DB ACL reconstruction (n = 9 knees). RESULTS: When compared with the intact knee, DB ACL reconstruction showed no significant difference in tibiofemoral contact area and mean and maximum pressures. SB ACL reconstruction had a significantly smaller contact area on the lateral and medial tibiofemoral joints at 30 degrees and 15 degrees of flexion. SB ACL reconstruction also had significantly higher mean pressures at 15 degrees of flexion on the medial tibiofemoral joint and at 0 degrees and 15 degrees of flexion on the lateral tibiofemoral joint, as well as significantly higher maximum pressures at 15 degrees of flexion on the lateral tibiofemoral joint. CONCLUSIONS: SB ACL reconstruction resulted in a significantly smaller tibiofemoral contact area and higher pressures. DB ACL more closely restores the normal contact area and pressure mainly at low flexion angles. CLINICAL RELEVANCE: Our findings suggest that the changes in the contact area and pressures after SB ACL reconstruction may be one of the causes of osteoarthritis on long-term follow-up. DB ACL reconstruction may reduce the incidence of osteoarthritis by closely restoring contact area and pressure.

Graft healing in anterior cruciate ligament reconstruction.

Graft healing within the bone tunnel after anterior cruciate ligament (ACL) reconstruction is still a complex, poorly understood biological process that is influenced by multiple surgical and postoperative variables. However, remarkable advances in knowledge of this process have been made based primarly on animal models. According to the findings of this review, some surgical and postoperative variables are known to directly affect time-course and quality of graft-tunnel healing. The type of graft, graft motion, and fixation methods have shown to directly affect time-course and quality of graft-tunnel healing. Therefore, the application of early and aggressive rehabilitation protocols should be cautious when using soft-tissue graft, allografts, and direct or aperture type of fixation for ACL reconstruction. With regard to graft placement, several cadaveric models showed biomechanical advantages of a more anatomical graft location; however, there are no studies that explore the relationship between graft placement and healing process. The precise effect of graft tensioning, graft/tunnel diameter disparity, and graft length within the bone tunnel in the graft healing process remains unclear and requires more research. To enhance graft-tunnel healing, tissue-engineering approaches, including the use of growth factors, mesenchymal stem cells, and periosteum graft augmentation, have been tested on animal models. These have shown promising results in terms of enhancement of bone-graft healing rate.

Topography of the femoral attachment of the posterior cruciate ligament.

BACKGROUND: The success of posterior cruciate ligament reconstruction has varied. The objective of this study was to determine quantitatively and qualitatively the topography and osseous landmarks of the femoral footprints of the anterolateral and posteromedial bundles of the posterior cruciate ligament in order to enhance repair. METHODS: Twenty unpaired knees from twenty human cadavers were evaluated. The surface features of the femoral footprints of the anterolateral and posteromedial bundles of the posterior cruciate ligament were studied by means of macroscopic observation and three-dimensional laser photography. RESULTS: We observed, both visually and with three-dimensional laser photography, an osseous prominence located proximal to the femoral footprint of the posterior cruciate ligament in eighteen of the twenty human knees. This osseous landmark, denominated the "medial intercondylar ridge," determined the proximal border of the posterior cruciate ligament footprint. In eight of the twenty knees, we observed a small osseous prominence between the anterolateral and posteromedial bundles of the posterior cruciate ligament. A clear change in the slope of the femoral footprint of the posterior cruciate ligament was seen between the anterolateral and posteromedial bundles. The average area of the posterior cruciate ligament footprint (and standard deviation) was 209 +/- 33.82 mm(2), the average area of the anterolateral bundle was 118 +/- 23.95 mm(2), and the average area of the posteromedial bundle was 90 +/- 16.13 mm(2). CONCLUSIONS: The femoral footprint of the posterior cruciate ligament has a unique surface anatomy, with a medial intercondylar ridge being frequently present and a medial bifurcate ridge being less frequently present.

Osseous landmarks of the femoral attachment of the anterior cruciate ligament: an anatomic study.

PURPOSE: Anatomic tunnel placement is critical to the success of anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to determine qualitatively and quantitatively the osseous landmarks of femoral attachment of the ACL. METHODS: The femoral attachment of the ACL was studied histologically in seven human fetuses, arthroscopically in 60 patients who underwent ACL surgery, and grossly in 16 cadaveric knees. Three-dimensional laser digitizer pictures of the cadaveric specimens were taken to quantify length, area, and angulations of the femoral attachment of the ACL. RESULTS: Two different osseous landmarks were detected. An osseous ridge that runs from proximal to distal ends was present in all the arthroscopic patients and cadaveric knees. It was named "lateral intercondylar ridge." Another osseous landmark between the femoral attachment of the anteromedial (AM) and posterolateral (PL) bundles running from anterior to posterior was observed in 6 out of 7 fetuses, 49 out of 60 arthroscopic patients, and 13 out of 16 cadaveric knees. It was named "lateral bifurcate ridge." A change of slope between the femoral attachment of the AM and PL bundles was observed in all specimens studied. The femoral attachment of the AM bundle formed an angle with the PL bundle of 27.6 degrees +/- 8.8 degrees and a radius of curvature of 25.7 +/- 12 mm. The area of the entire ACL footprint, AM, and PL bundle was 196.8 +/- 23.1 mm(2), 120 +/- 19 mm(2), and 76.8 +/- 15 mm(2), respectively. CONCLUSIONS: The ACL femoral attachment has a unique topography with a constant presence of the lateral intercondylar ridge and often an osseous ridge between AM and PL femoral attachment, the lateral bifurcate ridge. CLINICAL RELEVANCE: These findings may assist surgeons to perform ACL surgery in a more anatomic fashion.

Patellofemoral evaluation with radiographs and computed tomography scans in 60 knees of asymptomatic subjects.

PURPOSE: The objectives of this study were to show the results of patellofemoral joint imaging in healthy volunteers, to propose a standardization of the technique, and to test the statistical correlation and reliability of the different imaging results. METHODS: In 30 healthy police academy student volunteers of both sexes, standard knee radiographs and computed tomography (CT) scans were obtained. The angles and distances were measured, and a statistical analysis was applied. The results are presented as mean +/- 2 SDs throughout. RESULTS: The mean Laurin lateral patellofemoral angle on radiographs was 16.4 degrees +/- 8.7 degrees. The mean Insall-Salvati and Caton-Deschamps indexes were 1.09 +/- 0.24 and 0.95 +/- 0.29, respectively. The CT scan values for tilt were determined for the lateral patellofemoral angle by use of both facets (-8.1 degrees +/- 9.8 degrees), the Laurin lateral patellofemoral angle (8.1 degrees +/- 14.5 degrees), the condyle-patellar angle with the lateral facet (14.5 degrees +/- 14 degrees), and the patella major axis (-11.1 degrees +/- 10.6 degrees). The sulcus angle, congruence angle (Merchant angle), and condyle-lateral angle were also obtained on CT scans, with mean values of 139.7 degrees +/- 20.4 degrees , 5.15 degrees +/- 32.6 degrees , and 22.1 degrees +/- 9 degrees , respectively. The tibiofemoral rotation was assessed with the indexes for the distance between the trochlear groove and anterior tibial tuberosity and the distance between the posterior femoral dome and anterior tibial tuberosity. The values for these two indexes were 13.6 +/- 8.8 mm and 17.8 +/- 9.2 mm, respectively. Some parameters showed sex differences. CONCLUSIONS: There are good statistical correlations between some of the tilt values on the radiographs and CT scans, indicating that they move together. The values on the CT scans show good reliability. The CT scans and radiographs are good tests by which to evaluate and quantify patellar alignment. LEVEL OF EVIDENCE: Level I, testing of previously developed diagnostic criteria.