Navigated anterior cruciate ligament reconstruction: radiographic validation of a nonimage-based system

Intraoperative fluoroscopy shows better agreement and interchangeability in tibial tunnel location during single bundle anterior cruciate ligament reconstruction with postoperative three-dimensional computed tomography compared with an intraoperative image-free navigation system

BACKGROUND

Fluoroscopy and navigation systems provide an accurate and reproducible method of guiding anatomical tunnel positioning during anterior cruciate ligament reconstruction (ACLR). The aim was to evaluate the differences in tibial tunnel location assessed by both an intraoperative navigation system and fluoroscopy, validated using a one-week postoperative three-dimensional computed tomography (3DCT).

METHODS

The tibial tunnel location in a consecutive series of 35 patients who received a single-bundle ACLR was evaluated by intraoperative navigation system, fluoroscopic image and compared with postoperative 3DCT position. The location to the anterior-posterior (AP) and medial-lateral (ML) direction were compared between all three methods.

RESULTS

The tibial tunnel locations were 46.7 ± 4.5%, 44.5 ± 1.9%, and 43.6 ± 2.4% in ML direction, and 42.8 ± 7.6%, 37.9 ± 3.8%, and 37.9 ± 3.7% in AP direction using an intraoperative navigation system, fluoroscopic image and postoperative 3DCT, respectively. Significant differences between the navigation system and fluoroscopic image (ML, P = 0.001; AP, P = 0.006), and the navigation system and 3DCT (ML, P = 0.001; AP, P < 0.001) were seen. However, there was no significant difference between fluoroscopy and 3DCT (ML, P = 0.315; AP, P = 0.999). There was a significant lack of agreement for analyses measured using a navigation system and 3DCT. Fluoroscopy and 3DCT demonstrated an acceptable agreement (ML, r_pt = -0.21, P = 0.232; AP, r_pt = 0.04, P = 0.826).

CONCLUSIONS

A tibial tunnel location assessed by intraoperative fluoroscopy shows better agreement and interchangeability with one-week postoperative 3DCT validation during single-bundle ACLR compared with an intraoperative image-free navigation system.

An ACL reconstruction robotic positioning system based on anatomical characteristics

To improve the positioning accuracy of tunnels for anterior cruciate ligament (ACL) reconstruction, we proposed an ACL reconstruction robotic positioning system based on anatomical characteristics. The system includes a preoperative path planning system, an intraoperative path planning system, and a navigation and positioning system. Brahmet line, anterior, and posterior cortical lines are used for registration of preoperative computed tomography (CT) images and intraoperative X-ray images. A new calibrator of C-arm is applied to establish the mapping between medical images and surgical space. Tunnels for ACL reconstruction can be built anatomically by the robot. The accuracy of the path planning system is 1.73 mm in the four dry bones experiments and 2.17 mm in the two cadaver experiments. The accuracy meets the accuracy requirement of ACL construction surgery.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of anterior cruciate ligament injury - Secondary publication

BACKGROUND

This clinical guideline presents recommendations for the management of patients with anterior cruciate ligament (ACL) injury, endorsed by the Japanese Orthopaedic Association (JOA) and Japanese Orthopaedic Society of Knee, Arthroscopy and Sports Medicine (JOSKAS).

METHODS

The JOA ACL guideline committee revised the previous guideline based on "Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014", which proposed a desirable method for preparing clinical guidelines in Japan. Furthermore, the importance of "the balance of benefit and harm" was also emphasized. This guideline consists of 21 clinical questions (CQ) and 23 background questions (BQ). For each CQ, outcomes from the literature were collected and evaluated systematically according to the adopted study design.

RESULTS

We evaluated the objectives and results of each study in order to make a decision on the level of evidence so as to integrate the results with our recommendations for each CQ. For BQ, the guideline committee proposed recommendations based on the literature.

CONCLUSIONS

This guideline is intended to be used by physicians, orthopedic surgeons, physical therapists, and athletic trainers managing ACL injuries. We hope that this guideline is useful for appropriate decision-making and improved management of ACL injuries.

Arthroscopically assisted acromioclavicular joint stabilization leads to significant clavicular tunnel widening in the early post-operative period

PURPOSE

Arthroscopically assisted acromioclavicular joint (ACJ) stabilization techniques use bone tunnels in the clavicle and coracoid process. The tunnel size has been shown to have an impact on the fracture risk of clavicle and coracoid. The aim of the present study was to radiographically evaluate the alterations of the clavicular tunnel size in the early post-operative period. It was hypothesized that there would be a significant increase of tunnel size.

METHODS

Twenty consecutive patients with acute high-grade ACJ (Rockwood type IV-V) injury underwent arthroscopic-assisted ACJ stabilization. The median age of the patients was 40 (26-66) years. For all patients, a single tunnel button-tape construct was used along with an additional ACJ tape cerclage. Radiologic measurements were undertaken on standardized Zanca films at two separate time points, immediate post-operative examination (IPO) and at late post-operative examination (> 4 months; LPO). The LPO radiographs were taken at a median follow-up period of 4.5 (3-6) months. Clavicular tunnel width (CT) and coracoclavicular distance (CCD) were measured using digital calipers by two independent examiners and the results are presented as median, range, and percentage.

RESULTS

The median CCD increased significantly from 9.5 (8-13) mm at IPO to 12 (7-20) mm at LPO (p < 0.05). Median tunnel size showed significant difference from 3 (3-4) mm at IPO to 5 (4-7) mm at LPO (p < 0.05). Despite a significant increase of 2 mm (66.6%) of the initial tunnel size, there was no correlation between tunnel widening and loss of reduction.

CONCLUSION

Arthroscopic ACJ stabilization with the use of bone tunnels led to a significant increase of clavicular tunnel size in the early post-operative period. This phenomenon carries a higher fracture risk, especially in high-impact athletes, which needs to be considered preoperatively.

LEVEL OF EVIDENCE

IV.

Intensity-based 2D-3D registration for an ACL reconstruction navigation system

To improve the positioning accuracy of tunnels for anterior cruciate ligament (ACL) reconstruction, we proposed an intensity-based 2D-3D registration method for an ACL reconstruction navigation system. Methods for digitally reconstructed radiograph (DRR) generation, similarity measurement, and optimization are crucial to 2D-3D registration. We evaluated the accuracy, success rate, and processing time of different methods: (a) ray-casting and splating were compared for DRR generation; (b) normalized mutual information (NMI), Mattes mutual information (MMI), and Spearman's rank correlation coefficient (SRC) were assessed for similarity between registrations; and (c) gradient descent (GD) and downhill simplex (DS) were compared for optimization. The combination of splating, SRC, and GD provided the best composite performance and was applied in an augmented reality (AR) ACL reconstruction navigation system. The accuracy of the navigation system could fulfill the clinical needs of ACL reconstruction, with an end pose error of 2.50 mm and an angle error of 2.74°.

Arthroscopic fixation of acute acromioclavicular joint disruption with TightRope™: Outcome and complications after minimum 2 (2-5) years follow-up

PURPOSE

To evaluate the midterm results of arthroscopic reconstruction of acute acromioclavicular (AC) joint disruption using TightRope™ system.

METHODS AND MATERIAL

We retrospectively assess the results of 24 patients of acute AC joint dislocation who were operated using TightRope system. Constant and University of California, Los Angeles (UCLA) scores and coracoclavicular distance were calculated pre- and postoperatively. Data was entered into MS excel and analyzed using the SPSS version 17.

RESULTS

The mean follow-up was 39.45 months. Constant and UCLA scores were significantly increased postoperatively. Six patients had partial loss of reduction within 3-6 months and two patients had a failure of construct. Constant score was significantly lower in these patients.

CONCLUSION

TightRope reconstruction of the AC joint is a reproducible and safe alternative to many other techniques of AC joint reconstruction. Early subluxation remains a concern and may reflect the need for technique modification.

Current use of navigation system in ACL surgery: a historical review

PURPOSE

The present review aims to analyse the available literature regarding the use of navigation systems in ACL reconstructive surgery underling the evolution during the years.

METHODS

A research of indexed scientific papers was performed on PubMed and Cochrane Library database. The research was performed in December 2015 with no publication year restriction. Only English-written papers and related to the terms ACL, NAVIGATION, CAOS and CAS were considered. Two reviewers independently selected only those manuscripts that presented at least the application of navigation system for ACL reconstructive surgery.

RESULTS

One hundred and forty-six of 394 articles were finally selected. In this analysis, it was possible to review the main uses of navigation system in ACL surgery including tunnel positioning for primary and revision surgery and kinematic assessment of knee laxity before and after different surgical procedures. In the early years, until 2006, navigation system was mainly used to improve tunnel positioning, but since the last decade, this tool has been principally used for kinematics evaluation. Increased accuracy of tunnel placement was observed using navigation surgery, especially, regarding femoral, 42 of 146 articles used navigation to guide tunnel positioning. During the following years, 82 of 146 articles have used navigation system to evaluate intraoperative knee kinematic. In particular, the importance of controlling rotatory laxity to achieve better surgical outcomes has been underlined.

CONLUSIONS

Several applications have been described and despite the contribution of navigation systems, its potential uses and theoretical advantages, there are still controversies about its clinical benefit. The present papers summarize the most relevant studies that have used navigation system in ACL reconstruction. In particular, the analysis identified four main applications of the navigation systems during ACL reconstructive surgery have been identified: (1) technical assistance for tunnel placement; (2) improvement in knowledge of the kinematic behaviour of ACL and other structures; (3) comparison of effectiveness of different surgical techniques in controlling laxities; (4) navigation system performance to improve the outcomes of ACL reconstruction and cost-effectiveness.

LEVEL OF EVIDENCE

IV.

Patient-based decision for resuming activity after ACL reconstruction: a single-centre experience

PURPOSE

The purpose of the study was to report the functional outcome following anterior cruciate ligament (ACL) reconstruction in patients who decide when to resume work and normal sporting activity post-operatively. The hypothesis tested was that patient-based decision to return to work and sport was possible without compromising functional outcome and increased the rate of repeat rupture in comparison with the existing literature.

METHODS

This was a monocentric, retrospective study. Seventy-two patients requiring primary ACL reconstruction were included. All patients were followed up for a mean period of 4.3 years. Return to work and to sporting activity was allowed based on patient's decision. No restriction was suggested by the physician. Delays to return to work and sports and occurrence of graft failure were documented.

RESULTS

Sixty-six patients (92 %) returned to any sporting activity. The mean delay was 4.1 months for running, 6.1 months for pivoting sports, and 6.6 months for contact sports. Return to competitive sport was possible in 82 % of patients after a mean delay of 7.1 months. Return to work was possible for 96 % of patients after a mean delay of 2.3 months. Index Tegner score normalized in 71 % of patients. Four repeat ruptures (6 %) were observed, all of them following a significant knee injury.

CONCLUSIONS

Patient-based decision to return to work and sport was possible without compromising functional outcome. The post-operative restrictions implemented by orthopaedic surgeons following ACL reconstructions may be relaxed and more patient based.

Importance of additional temporary pin fixation combined coracoclavicular augmentation using a suture button device for acute acromioclavicular joint dislocation

INTRODUCTION

We evaluated the outcomes of coracoclavicular (CC) augmentation using a suture button device with additional temporary pin fixation for acute acromioclavicular (AC) joint dislocation.

MATERIALS AND METHODS

Thirty-six consecutive cases who underwent CC augmentation using TightRope™ (Arthrex, Naples, FL, USA) were included. We temporarily fixed trans-articular pins in the first 10 cases (TA group) and a trans-spine pin in the next 26 cases (TS group). The radiological and clinical outcomes were evaluated at minimum 2 years postoperatively.

RESULTS

The mean follow-up period was 56.7 months (range, 24-84 months). At the final follow-up evaluation, reduction status showed anatomical reduction in 25 cases (69.4 %), slight loss of reduction in seven cases (19.4 %), partial loss of reduction in two cases (5.6 %), and total loss of reduction in two cases (5.6 %). The mean ASES score, UCLA score, and subjective shoulder value were 92.3, 32.9, and 91.6 %, respectively. There were no significant differences between the two groups with respect to the outcomes. Intraoperative complications occurred in three cases (8.3 %) including two cases of failed reduction and one case of technical failure of the implant. Postoperative complications occurred in three cases (8.3 %) including one case of pin tract infection and distal clavicle fracture at the clavicle-hole, one case of reduction loss by severe subsidence of the clavicular button, and one case of shoulder stiffness.

CONCLUSIONS

CC augmentation using a suture button device with temporary pin fixation yielded satisfactory radiological and clinical outcomes. These results support that temporary pin fixation for the AC joint may help to protect the AC reduction in the early phase of healing and rigid scar formation when performing CC fixation using a suture button device.

LEVEL OF EVIDENCE

Level-IV, Retrospective Case Series, Treatment Study.

Bone mineral density of the coracoid process decreases with age

PURPOSE

Surgical options in the treatment of recurrent anterior shoulder instability are numerous. The Latarjet procedure is one of the most common procedures performed. It has been previously demonstrated that bone mineral density decreases with age. This reduction thus increases the risk of osteoporosis and osteoporosis-related iatrogenic, traumatic or pathological fractures. The objective of this study was to quantify the bone mineral density of the coracoid process in different age groups. The hypothesis was that mineral bone density of the coracoid process decreases with age.

METHODS

Using the hospital's electronic database, 60 patients who underwent a shoulder CT scan were randomly selected retrospectively. Four groups of 15 were formed with mean ages of 20, 30, 40 and 50 years. Bone density, length, width and thickness of the coracoid process 10 mm from the tip were measured four times by two different evaluators. Bone density was expressed in Hounsfield units (HU).

RESULTS

The mean bone mineral density of the coracoid process significantly decreased with age (p < 0.0001). A lower but insignificant difference of bone mineral density was observed in females. A good inter- and intra-observer reliability was found for bone mineral density measurement of the coracoid process (0.67 and 0.7, respectively).

CONCLUSIONS

The bone mineral density of the coracoid process diminishes with age, thus confirming our hypothesis. There is a good inter- and intra-observer reliability of our CT scan-based coracoid process bone mineral density measurement rendering it reproducible in daily clinical practice.

LEVEL OF EVIDENCE

IV.

Effects of extremity positioning on radiographic evaluation of femoral tunnel location with digitally reconstructed femoral lateral radiographs after anterior cruciate ligament reconstruction

Background

Radiographic imaging is a valuable tool in clinical practice for quick anatomical assessment. We aimed to radiographically assess (A) the anterior cruciate ligament (ACL) graft tunnel location after anatomic single-bundle (SB) reconstruction and (B) the effects of extremity positioning on the localization of the orifice of the tunnel in the distal femur in comparison with Blumensaat’s line (BL).

Methods

Three-dimensional computed tomography (3D CT) scan examinations of 22 knees of 22 subjects were evaluated. The 3D CT scan data was used to digitally reconstruct the true lateral radiographs. Graft tunnel location on the distal femoral shaft along the Blumensaat’s line and perpendicular to it were assessed on these radiographs. The femur was digitally rotated to simulate varus, valgus, internal rotation and external rotation in 5-degree increments from 0 to 20-degree. At each incremental rotated position of the femur, position of the ACL graft tunnel was calculated relative to BL and the difference from the true lateral x-ray was estimated.

Results

The position of the tunnel in the distal femur was 30.6 (±4.4) % along BL and 33.1 (±5.4) % perpendicular to BL. Ten and more degree of external, internal, valgus and varus rotations significantly affected the estimates of tunnel position (P < 0.05).

Conclusions

Femoral tunnel location can be reliably estimated from lateral radiographs after anatomic SB ACL reconstruction. Although, ten or more degree of rotations can introduce significant inaccuracies in tunnel location estimates, our study suggests that BL is overall reliable for assessing location of the distal femoral tunnel. Level of evidence: Level 2b (Retrospective Cohort Study).

Variability of landmark acquisition affects tunnel calculation in image-free ACL navigation

PURPOSE

The purpose of this study was to determine the inter- and intraobserver variability of intraarticular landmark identification for tunnel position calculation in image-free anterior cruciate ligament (ACL) navigation.

METHODS

In a test/retest scenario, thirteen experienced ACL surgeons (>50 reconstructions year) experienced in image-free ACL navigation were asked to identify the landmarks required for image-free ACL navigation in the same cadaver knee. Landmark positions were registered using a fluoroscopic ACL navigation system. Positions were determined using validated radiological measurement methods. For variability analysis, mean positions, deviations between the test/retest positions, standard deviations (SD) and range were calculated.

RESULTS

Interobserver analysis showed a mean variability (SD) for the tibial landmark positions of 3.0 mm with deviations of up to 24.3 mm (range). Mean femoral landmark variability was 2.9 mm (SD) with deviations of up to 11.3 mm (range). Intraobserver analysis showed a tibial reproducibility of 2.2 mm (SD 2.0 mm; range 10.9 mm) and a femoral of 1.9 mm (SD 1.9 mm; range 10.4 mm).

CONCLUSION

The data of the presented study suggest that a considerable inter- and intraobserver variability in intraarticular landmark identification exists. Reasonable ranges were found that have to be considered as a potential risk for miscalculation of tunnel positions in image-free ACL reconstruction.

CLINICAL RELEVANCE

Landmark acquisition affects tunnel calculation in image-free ACL.

LEVEL OF EVIDENCE

IV.

[Therapy of acute acromioclavicular joint instability. Meta-analysis of arthroscopic/minimally invasive versus open procedures]

BACKGROUND

A variety of surgical procedure are desrcibed for the treatment of acute acromioclavicular (AC-) joint injuries. Beside open techniques arthroscopic assisted procedures spread widely. Each surgical technique offers advantages and disadvantages, but none is currently accepted as a gold standard. Therefore, the study aims to review the evidence for arthroscopic and open surgical procedures in the treatment of acute AC joint instabilities.

MATERIAL AND METHODS

According to the Cochrane Handbook for Systematic Reviews of Interventions we conducted a defined search of Medline and Embase database for articles publisher over the last ten years.

RESULTS

The search resulted in 961 studies of which 32 were included in this review and 3 studies were suitable for a meta-analysis. The functional outcome (Constant score) showed a tendency towards better results after arthroscopic procedures (weighted mean difference 5.60, 95% confidence interval 0.36-10.64). There were no significant differences with respect to complication rates, secondary dislocation in the vertical plane, revision surgery and AC joint instability.

CONCLUSION

There is insufficient evidence to inform the surgical management of acute AC joint instability. Due to inconsistent study designs there is no evidence for a general superiority of any of the open or arthroscopic procedures. Randomized, controlled studies are necessary to demonstrate whether arthroscopic techniques show a potential benefit in terms of a better functional outcome.

Evaluation of coracoclavicular stabilization of acute acromioclavicular joint dislocation with multistrand titanium cables

PURPOSE

The aim of this study was to evaluate the outcome of surgical treatment of acute acromioclavicular (AC) joint dislocation with multistrand titanium cables for coracoclavicular (CC) stabilization.

METHODS

Forty-two patients with acute AC joint dislocation, including Rockwood type III 14 cases, type IV 2 cases and type V 26 cases, were operated with CC stabilization using multistrand titanium cables. The cables were removed 3-12 months after surgery. The function outcome was evaluated by Constant scores and visual analog scale (VAS) scores. Radiological examination included bilateral antero-posterior and axillary radiography.

RESULTS

Three patients were lost to follow-up. Thirty-nine patients had an average follow-up time of 42 months (range 34-60). The Constant scores were 95.3 ± 9.3 at final evaluation. Preoperative and final follow-up VAS scores were 5.6 ± 1.5 and 0.4 ± 1.2, respectively (P < 0.05). Radiographs showed anatomical reduction in 32 patients. Cables breakage occurred in two patients.

CONCLUSIONS

CC stabilization with multistrand titanium cables was an effective and safe alternative to other procedures for the treatment of acute high-grade AC joint dislocations. It can provide immediate joint stabilization and allow early mobilization of limb with satisfied functional recovery.

Radiographic changes in the operative treatment of acute acromioclavicular joint dislocation - tight rope technique vs. K-wire fixation

Background

Operative treatment of higher degree acromioclavicular joint luxation is common. A new option is made available by the tight rope technique. It claims to provide adequate outcome with the use of a minimally invasive technique. First clinical studies justified its medical use, but the equivalence to established surgical methods remains unclear. We therefore analyzed radiographic data from patients that were treated with the tight rope system (TR) and compared them to those treated with K-wires (KW) fixation.

Material/Methods

Retrospective study with inclusion criteria: surgery for acromioclavicular joint luxation between 2004 and 2011, classified as Rockwood type III, no concomitant injury, first event injury. We compared pre- and post-operative X-rays with those taken at the end of treatment. Clinical data from follow-ups and radiographic data were evaluated. The main outcome variable was the remaining distance between the acromion and clavicle (ACD), as well as the coracoid process and clavicle (CCD).

Results

27 patients (TR: n=16; KW: n=11) with comparable demographics and injury severity were included. Surgery reduced ACD (TR: p=0.002; KW: p<0.001) and CCD (TR: p=0.001; KW: p=0.003). Heterotopic ossification or postoperative osteolysis was not significantly associated with either one of the procedures. Three patients (18.75%) in the TR group showed impaired wound healing, migrating K-wires were recorded in 2 patients (18.2%) and impingement syndrome occurred in 1 patient (9.1%) with K-wires. Posttraumatic arthritis was not seen. There was a loss of reduction in 2 cases within the TR-group (12.51%) and 1 in the KW-group (9.1%). At last follow up, ACD and CCD were wider in both groups compared to the healthy side.

Conclusions

This study shows that the Tight rope system is an effective alternative in the treatment of higher degree acromioclavicular luxation and comparable to the established methods.